a r X i v :a s t r o -p h /0701539v 1 18 J a n 2007
Draft version February 5,2008
Preprint typeset using L A T E X style emulateapj v.10/09/06
THE NATURE OF OPTICAL FEATURES IN THE INNER REGION OF THE 3C 48HOST GALAXY 1
Alan Stockton 2,3,Gabriela Canalizo 4,Hai Fu 2,and William Keel 5
Draft version February 5,2008
ABSTRACT
The well-known quasar 3C 48is the most powerful compact steep-spectrum radio-loud QSO at low redshifts.It also has two unusual optical features within the radius of the radio jet (～1′′):(1)an anomalous,high-velocity narrow-line component,having several times as much ?ux as does the narrow-line component coinciding with the broad-line redshift;and (2)a bright continuum peak (3C 48A)～1′′northeast of the quasar.Both of these optical features have been conjectured to be related to the radio jet.Here we explore these suggestions.
We have obtained Gemini North GMOS integral-?eld-unit (IFU)spectroscopy of the central region around 3C 48.We use the unique features of the IFU data to remove unresolved emission at the position of the quasar.The resolved emission at the wavelength of the high-velocity component is peaked 0.′′25north of the quasar,at virtually the same position angle as the base of the radio jet.These observations appear to con?rm that this high-velocity gas is connected with the radio jet.However,most of the emission comes from a region where the jet is still well collimated,rather than from the regions where the radio maps indicate strong interaction with an external medium.
We also present the results of HST STIS spectroscopy of 3C 48A.We show that 3C 48A is dominated by stars with a luminosity-weighted age of ～1.4×108years,substantially older than any reasonable estimate for the age of the radio source.Our IFU data indicate a similar age.Thus,3C 48A almost certainly cannot be attributed to jet-induced star formation.The host galaxy of 3C 48is clearly the result of a merger,and 3C 48A seems much more likely to be the distorted nucleus of the merging partner,in which star formation was induced during the previous close passage.Subject headings:galaxies:high-redshift—galaxies:formation—galaxies:evolution
1.INTRODUCTION
3C 48(z =0.369)is a remarkable quasar quite aside from the fact that it was the ?rst to be identi?ed (Matthews et al.1961;Matthews &Sandage 1963).As seems to be the case with a number of “prototypes,”it is far from typical.The original identi?cation of 3C 48de-pended in part on the small size of its radio source,and 3C 48and 3C 277.1remain the only examples of com-pact steep-spectrum (CSS)radio sources among power-ful quasars at redshifts <0.5.The host galaxy of 3C 48is unusually large and bright in comparison with those of other low-redshift quasars (Kristian 1973).It is now rec-ognized that these host galaxy properties are largely a result of a major merger (Stockton &MacKenty 1987;Canalizo &Stockton 2000;Scharw¨a chter et al.2004).3C 48was the ?rst quasar for which an extended dis-tribution of ionized gas was observed (Wampler et al.
1
Based in part on observations made with the NASA/ESA Hub-ble Space Telescope,obtained at the Space Telescope Science In-stitute,which is operated by the Association of Universities for Research in Astronomy,Inc.,under NASA contract NAS 5-26555.These observations are associated with program #GO-09365.Also based in part on observations obtained at the Gemini Observatory,which is operated by the Association of Universities for Research in Astronomy,Inc.,under a cooperative agreement with the NSF on behalf of the Gemini partnership:the National Science Foun-dation (United States),the Particle Physics and Astronomy Re-search Council (United Kingdom),the National Research Coun-cil (Canada),CONICYT (Chile),the Australian Research Council (Australia),CNPq (Brazil)and CONICET (Argentina).2Institute for Astronomy,University of Hawaii 3Cerro Tololo Inter-American Observatory
4Department of Physics and Astronomy and Institute of Geo-physics and Planetary Physics,University of California at Riverside 5Department of Physics and Astronomy,University of Alabama
1975),and it still is one of the most luminous ex-amples of extended emission among low-redshift QSOs (Stockton &MacKenty 1987).It is one of a handful of previously identi?ed QSOs to have been shown by IRAS also to be ultraluminous IR galaxies.Star for-mation is currently underway at a prodigious rate in the inner part of the host galaxy (Canalizo &Stockton 2000),and there are still massive reserves of molecu-lar gas (Scoville et al.1993;Wink,Guilloteau,&Wilson 1997).All things taken together indicate that we are witnessing a brief but important phase in the history of a quasar,a time when host-galaxy star formation is near its peak,the radio jet is breaking through the dense ma-terial in the inner part of the host galaxy,and UV radia-tion from the central continuum source has just recently become visible along many lines of sight.
Wampler et al.(1975)noticed that the [O III ]pro-?le in 3C 48was signi?cantly blueshifted relative to the broad H βline.Higher-resolution spectroscopy of the quasar (Chatzichristou,Vanderriest,&Ja?e 1999;Canalizo &Stockton 2000)shows the reason for this ap-parent shift:in addition to the usual nuclear narrow-line region,there is very luminous extended high-velocity gas within about 0.′′5of the nucleus.Chatzichristou et al.(1999)presented evidence from their integral-?eld-unit spectroscopy that the high-velocity gas has been acceler-ated by the interaction of the radio jet with the surround-ing medium.They discussed the variation of relative line ratios,velocities,and line widths of the high-velocity and systemic-velocity components.Canalizo &Stockton (2000)found that the high-velocity gas was resolved on a slit through the nucleus at position angle ?28?,with an extent of ～0.′′5and a discernible velocity gradient.But
2
neither of these studies had su?cient spatial resolution to explore the detailed relation between the radio jet and
the high velocity gas.
Boroson&Oke(1982,1984)long ago showed the presence of strong Balmer absorption in the3C48 host galaxy.Canalizo&Stockton(2000)examined the host galaxy of3C48in more detail with the Keck Low-Resolution Imaging Spectrograph(LRIS;Oke et al. 1995)and showed that the spectrum of the stellar pop-ulation had a classic“K+A”character.The fact that they saw Balmer absorption lines from a relatively young stellar population as well as evidence for an older popu-lation(e.g.,from the Mg I b feature at～5180?A)meant that they could do a decomposition of the two compo-nents(using stellar synthesis models,such as those of Bruzual&Charlot1993,2003)and estimate,at least in a relative sense,the time that had elapsed since the end of the major starburst phase.With su?cient signal-to-noise,it is possible to carry out such a decomposition at each point in the host galaxy,building up a map of starburst ages along lines of sight through the host
galaxy(strongly weighted towards the time at which the most recent major episode of star formation ceased). Canalizo&Stockton(2000)were able to determine star-burst ages and stellar radial velocities in32distinct re-gions.
But one of the most interesting features in the host galaxy was too close to the quasar to permit su?-ciently low levels of contamination from quasar light to extract the galaxy spectrum.This is the lumi-nosity peak3C48A～1′′northeast of the quasar,?rst noticed by Stockton&Ridgway(1991)and con-?rmed by subsequent groundbased and HST observa-tions(Chatzichristou et al.1999;Kirhakos et al.1999; Boyce et al.1999;Canalizo&Stockton2000).One of our ground-based images is shown in Fig.1a,and HST PC images obtained from the archive are shown in Fig.1b and c.Stockton&Ridgway(1991)originally suggested that3C48A was the secondary nucleus from a merging companion;this suggestion was consistent with the pres-ence of the tidal tail to the northwest,as well as ev-idence that we are seeing the3C48host galaxy near the stage of?nal merger(Canalizo&Stockton2000). The attempt to model the merger by Scharw¨a chter et al. (2004)shows that there is short period during which the two nuclei would have a separation and position angle roughly similar to that observed for3C48and 3C48A.On the other hand,the morphology of the CSS radio jet(Wilkinson et al.1991)and the presence of the high velocity emission-line components near the quasar (Chatzichristou et al.1999;Canalizo&Stockton2000) both suggest that there is a strong interaction between the radio jet and the ambient gas in the general region of 3C48A.3C48A is dominated by continuum radiation;
i.e.,the o?set peak is seen on continuum images but not on narrow-band[O III]images(Stockton&Ridgway 1991;Canalizo&Stockton2000).However,there is no detailed correspondence between the morphology of the jet and that of3C48A(the jet proceeds nearly north-wards rather than northeasterly),so the optical emission from3C48A cannot be due to synchrotron radiation. It clearly is unlikely to be nebular thermal continuum from an interaction of the jet and the gas,because we would expect fairly strong emission-line radiation at rea-
Fig. 1.—a—Our deep line-free-continuum groundbased image of3C48,after removing the quasar nucleus with the STSDAS pro-cedure cplucy.The cross marks the position of the quasar.3C48A lies about1′′NE of the nucleus(North is up and East to the left).All insets show the central region of the corresponding main panel at lower contrast.b and c—HST PC images from the HST archive.The nucleus has been removed with synthetic Tiny Tim PSFs,so there are large residuals in the inner0.′′5radius and in the di?raction spikes.The scale of these panels is enlarged by a factor of2from that of a.The?lter bandpasses are indicated.d—Enlargement(by another factor of2)of the inner region of the HST PC F555W image,showing the position and width of the STIS slit.
sonable temperatures.Chatzichristou et al.(1999)?nd colors for3C48A consistent with stars with ages simi-lar to the likely age of the radio jet( 107years).The HST images show that3C48A is curiously distorted;this distortion could result either from the shape of an over-pressured region resulting from shocks from the radio jet or from the tidal stretching of the nucleus of a merging companion.
Here we use Gemini Multi-Object Spectrograph (GMOS)integral-?eld-unit(IFU)spectroscopy to ana-lyze more precisely the position and extent of the high-velocity emission,and spectroscopy with the Space Tele-scope Imaging Spectrograph(STIS)on the Hubble Space Telescope(HST)to attempt to determine the nature of 3C48A.Our principal goals for the STIS observations are (1)to determine whether the continuum radiation asso-ciated with3C48A is indeed due to stars;if so,(2)to de-termine the ages of the stellar populations involved and whether there is an age discontinuity;and(3)to mea-sure velocities of the stellar component:do these show any evidence for distinct kinematical signature,such as might be expected if3C48A is the distorted nucleus of a merging companion.We assume a?at cosmology with ?m=0.3and H0=70km s?1Mpc?1.
2.OBSERVATIONS AND DATA REDUCTION
2.1.Gemini North GMOS Integral-Field-Unit
Spectroscopy
We obtained two-dimensional spectroscopy of the cen-tral region of3C48with the integral-?eld mode of GMOS on the Gemini North Telescope(program ID no.GN-
3 2003B-C-5).We used the half-?eld mode with the B600
grating,which gave a?eld of3.′′3×4.′′9and a wavelength
range of4318–7194?A.The lenslets have a width of0.′′2,
and the CCD pixels correspond to0.′′05.The total expo-
sure was9000s,obtained as51800s exposures.Observa-
tions of the spectrophotometric standard star G191B2B
provided the?ux calibration.
The raw spectral images were processed with the stan-
dard Gemini IRAF routines to give the?ux calibrated
data cube.The6256spatial planes of the data cube have
dimensions of66×98pixels(0.′′05square)and are spaced
at intervals of0.46?A.This data cube still su?ers from
the e?ects of atmospheric dispersion.Since the quasar
was included within the?eld of view,we were able to
determine its centroid for each spatial plane of the data
cube.We?tted a low-order cubic spline curve to the plot
of each of the coordinates as a function of wavelength and
used these to generate correction o?sets for each plane
of the data cube.Applying these corrections generated
a new data cube for which all of the image planes were
correctly registered.The?eld of view for which the full
range of wavelengths is available is,of course,somewhat
smaller than the nominal?eld because of the atmospheric
dispersion.This corrected data cube was used for anal-
ysis when we had to deal with a large wavelength range.
However,for our detailed analysis of the[O III]pro?le,
we used the uncorrected data cube,as described in§3,
in order to avoid unnecessary interpolation.The?nal
image resolution at6800?A(near redshifted[O III])was
0.′′55(FWHM).
2.2.HST STIS Spectroscopy
The STIS spectroscopy was carried out with the G430L
grating,covering a nominal region from2900?A to5700
?A.The slit was centered at a position0.′′97east and0.′′50
north of the quasar,at a position angle of44.?74.The
e?ciency decreases quite drastically towards the UV end
of the spectrum,and the useful spectral range for our
project was restricted to3630?A to5685?A.Because of
the low surface brightness of3C48A,we used the0.′′5slit
and binned by2pixels in the dispersion direction,obtain-
ing a total of21076s of integration over8orbits.The
spectra were dithered over4positions along the slit.The
slit position,superposed on the HST PC F555W image,
is shown in Fig.1d.We also obtained626s of integra-
tion on the quasar itself with the same con?guration,but
without binning.
Each of the8individual spectra of3C48A was?rst
given a preliminary cleaning of cosmic rays with la-
cos
4
to eliminate the broad Hβline in the residual.We show the region of Hβand[O III]λλ4959,5007lines after this subtraction for our6o?-nuclear B apertures(centered 1.′′1from the quasar)in Fig.3(left panel),as well as the same region for the quasar.In the right panel of Fig.3,we show similarly subtracted spectra for the A apertures(centered0.′′4from the quasar).For the aper-tures at1.′′1radius(left panel in Fig.3,the high-velocity component shows up most strongly in the B0and B60 apertures;it is essentially completely absent in the B180, B240,and B300apertures.There is a clear velocity o?set of the high-velocity component between the B0and B60 apertures,as well as evidence for more than two velocity components in the former.The high velocity emission is much stronger in the inner apertures,particularly the A0aperture,where the?ux has over10times the high-est value that it has in any of the outer apertures.It is absent from the A120,A180,and A240apertures,but present in the A60and A300apertures.For this inner ring of apertures,the aperture boundaries are adjacent to each other,so there will be unavoidable spill-over be-cause of the0.′′55FWHM seeing disk.
At?rst sight,it may appear that is a problem with the subtraction procedure because of negative[O III] residuals,particularly in the A180spectrum.Note,how-ever,that these negative excursions are only at the wave-length of the high-velocity component.The explanation is almost certainly that the quasar aperture encompasses high-velocity emission slightly extended to the north, which is then excess to the scattered nuclear quasar con-tribution to apertures on the south side.
In order to explore the spatial distribution of the high-velocity material in more detail,we analyze the image planes of the data cube as we step across the[O III]line pro?le.Since we are here concentrating on a very small range of wavelengths around the[O III]λ5007emission complex,we can use the original data cube,uncorrected for atmospheric dispersion,thus avoiding any smearing from subpixel interpolation.The maximum shift due to dispersion was con?rmed to be less than0.1pixel(= 0.′′005)over this wavelength range.The general approach is this:we use the continuum on either side of the[O III]λ5007line to precisely de?ne the PSF of the quasar;we bin narrow wavelength intervals to form images from the data cube as we step across the line pro?le,and we then subtract a scaled PSF from each of these to show the distribution of extended emission close to the quasar for each part of the line pro?le.
In more detail,we used narrow regions of continuum (～20?A wide)immediately on either side of the emission line to de?ne the PSF centroid at the line,but we used wider(～100?A)continuum regions somewhat farther away to obtain better S/N for the PSF pro?le itself.This high S/N PSF was then carefully registered(at the sub-pixel level)to the PSF at the emission-line wavelength. We used114.6-?A-wide slices to span the double line pro-?le.For each of these images,we ran the two-component deconvolution task plucy(Hook et al.1994).Brie?y, plucy allows separate treatment of point sources(which can be removed)and a variable background compo-nent,which is deconvolved via the Richardson-Lucy algo-rithm,subject to an adjustable entropy constraint.The result was that any unresolved nuclear emission(i.e.,that having a distribution indistinguishable from that of the quasar continuum)was removed,and only extended emission was retained in the residual images.These im-ages are shown in Fig.4,along with the location in the line pro?le each represents.We also show the radio jet (Feng et al.2005)at the same scale.What is immedi-ately clear is that the high-velocity emission is concen-trated to the north of the quasar,precisely in the initial direction of the radio jet,and mostly within the region where the jet appears relatively unperturbed.There is some slight variation in the position and shape of the distribution of emission across the high-velocity line pro-?le,and there is a tail of emission at high velocities to the east,but the main emission peak remains closely aligned with the radio jet.As the wavelength window shifts towards the systemic redshift,the centroid of the extended emission moves more to the west,and more low-surface-brightness extended emission at greater distances becomes visible,including a possible ring of emission at about1′′radius from the quasar.Our decomposition of the pro?le indicates that the narrow-line emission com-ponent at the systemic velocity is dominated by the high-velocity component at all points in the composite pro?le. The contribution of the systemic component is greatest (almost50%)near its peak,but it drops o?sharply at higher(as well as lower)velocities,because of the much broader velocity width of the high-velocity emission.We also expect the classical narrow-line region to be more closely centered on the nucleus and to be mostly unre-solved.Reconstruction of the line pro?le from the de-convolved,PSF-subtracted images tends to bear out this expectation,although some residual systemic narrow-line emission still remains,perhaps indicating that this region is slightly resolved(see also the pro?le in the A0aper-ture in Fig.3).However,the shift in the centroid of the emission must still largely be due to a gradient in the high-velocity component,rather than any extension of the classical narrow-line region.
From an aperture that includes essentially all of the high-velocity emission,our decomposition of the[O III] pro?le gives a value of491±40km s?1for the velocity o?set between the two systems in the rest frame of the quasar.The[O III]?uxes in the two components are 2.9×10?13and4.1×10?14erg s?1cm?2,respectively,for the high-velocity and systemic velocity components;i.e., the high-velocity gas has～7times the[O III]luminosity of that of the classical narrow-line region.
We have attempted to estimate contributions to the Hβpro?le from these two narrow-line components.We take the best-?tting Gaussian decomposition of the[O III] pro?le,shift these to the appropriate positions and widths for Hβat the same redshifts,and scale the two components independently to obtain the maximum sub-traction consistent with a smooth and fairly symmetric core for the Hβresidual.This procedure gives a narrow-line Hβ/[O III]ratio of～0.1for the systemic-velocity component and～0.08for the high-velocity component. We have also carried out decompositions of the[O II]λ3727doublet and the[Ne V]λ3425line.The[O II] case is complicated by the uncertainty in the density-dependent doublet line ratio for each of the components, but the formal best?t gives a line ratio at or near the low-density limit and a total?ux～16%of that of[O III]λ5007for the high-velocity component and a line ratio
5
Fig.3.—(left panel)Spectra of the region around the Hβand[O III]λλ4959,5007lines for the same apertures as are shown in Fig.2; but,in this case,a scaled quasar spectrum has been subtracted from each of the o?-nuclear spectra to remove the scattered quasar light,as judged by the broad Hβemission.(right panel)Similar quasar spectra for apertures at a radius of0.′′4from the quasar.The B60spectrum at the bottom,shown at the same scale as the other spectra,indicates the relative scaling for the two panels.
near unity(indicating an electron density of a few hun-
dred per cm3)and a total?ux～25%of that of[O III]
λ5007for the component at the systemic velocity.For
the[Ne V]line,the high-velocity and systemic compo-
nents have?uxes around14%and20%of those of their
respective[O III]pro?les.Our ratios for the two veloc-
ity systems for Hβ/[O III]and[O II]/[O III]are quite
consistent with those reported by Chatzichristou et al.
(1999).All in all,the ionization parameters of the two
components seem roughly similar.
From our estimate of the Hβ?ux in the high-velocity
component,and assuming an electron density and tem-
perature,the mass of the ionized gas in this component
is given by
4πm p f Hβd2L
M H=
6
Fig. 4.—The location of nuclear[O III]extended emission in3C48.The unresolved nuclear emission component has been removed from these images using plucy(Hook et al.1994),where the PSF has been determined from the average continuum pro?le on either side of the[O III]line.The black dot marks the position of the quasar.The[O III]line pro?le is shown to the left of each image,and the green bar indicates the wavelength region that has been summed to form the corresponding image.The number in the upper-left corner of the images gives the central velocity shift of the image,in km s?1in the quasar frame,from the systemic redshift of0.36933.The5 GHz Merlin radio contours from Feng et al.(2005)are shown superposed on the image near the peak of the high-velocity system in the lower-right panel.All images use a common intensity mapping and have North up and East to the left.
panel),we overplot on the spectrum Bruzual&Charlot (2003)solar-metallicity instantaneous-burst models with ages ranging from100to200Myr,which appear to bracket the luminosity-weighted average age of the stars (we also include a10-Myr model for reference).The best ?t,judged by the slope of the continuum shortward of the Balmer limit,is about140Myr.We have explored the possibility of younger stellar ages,combined with internal reddening,as a means of trying to?t the ob-served spectrum.The fundamental di?culty with this approach is the rapid decrease in the amplitude of the Balmer-limit break at ages below100Myr,as shown in the right panel of Fig.5.Because of the short wave-length interval involved(from～3600?A to～4000?A), the break cannot be signi?cantly enhanced by redden-ing without doing unacceptable violence to the rest of the spectrum,and this conclusion holds for any plausi-ble reddening law.It has previously been noted(see, e.g.,Chatzichristou et al.1999)that our particular line of sight to3C48must have little or no signi?cant red-dening,in spite of the evidence for a major starburst in the host galaxy,and this conclusion seems to hold for 3C48A as well,in spite of suggestions to the contrary by Zuther et al.(2004).
The fact that there is some evidence for a Ca II K line stronger than in our models give encouraged us to try combinations of an old stellar population with a younger one.Such a composite population might be expected to allow a younger age for the young population.(Recall, however,that the host galaxy background near3C48A has been subtracted o?to?rst order by our reduction procedure,so that any signi?cant older population would likely have to be from3C48A itself).The general results of these experiments are that it is di?cult to add any sub-stantial fraction(by light)of old stars without unaccept-able decreases in both the Hδstrength and the Balmer break amplitude,and,even with a fairly large fraction of old stars(20%at rest-frame4050?A),the younger com-ponent still could not be much younger than108years. While the di?culties of attempting to obtain a clean spectrum of3C48A from ground-based observations are formidable because of scattered quasar light(and par-ticularly the di?culty of correcting for its wavelength variation)as well as contamination from other parts of
7
Fig. 5.—Both panels show the HST STIS spectrum of 3C 48A (black trace).The left-hand panel shows a 140-Myr-old Bruzual &Charlot (2003)instantaneous-burst spectral synthesis model (red trace),and the green and blue traces show 100-Myr and 200-Myr models,respectively.The right-hand panel shows a range of more extreme models with
ages from 10-Myr (which would be consistent with an estimate of the upper limit to the age of the stellar population in 3C 48A obtained by Chatzichristou et al.1999)to 2Gyr.Note that the Balmer lines and Balmer break constrain the possibility of trying to ?t younger populations with substantial reddening to the data.
Fig. 6.—Spectra and models of 3C 48A.The black trace is the spectrum of the 60?aperture,after subtracting the mean of the other o?-nuclear apertures and scaling to match the HST STIS spectrum,which is shown in red.The green trace is the long-wavelength portion of the Bruzual &Charlot (2003)140Myr model,using the same scaling as the same model in the left panel of Fig.5.
the host galaxy,we were encouraged by the fact that our 60?aperture,which covers 3C 48A,shows a substan-tially higher continuum level than the other apertures,even in the uncorrected spectra shown in Fig.2.We tried simply subtracting a straight mean of the other 5o?-nuclear apertures,which are all at the same distance from the quasar.If the quasar pro?le is closely symmet-ric,this procedure should remove the scattered quasar light reasonably well.It will also,to ?rst order,subtract the host-galaxy background,although there is certainly no guarantee that this will be very accurate,because of variations in the host galaxy surface brightness.The re-sult is shown in Fig.6.
Naturally,one must be wary of putting too much trust in the details of this residual spectrum because of varia-tions among the 5spectra that have been subtracted from it.Nevertheless,it does agree with the general features of the STIS spectrum remarkably well,and it reinforces the conclusion that the dominant stellar population in 3C 48A must be old enough to show a substantial Balmer break.
These results are di?cult to reconcile with the sug-gestion that 3C 48A is in some way connected with the radio jet.The fact that 3C 48A is dominated by stel-lar radiation eliminates any possibility that it is due to any form of gaseous emission or emission connected with relativistic electrons,such as synchrotron radiation or Compton upscattering of photons.Dust scattering of starlight from elsewhere in the host galaxy is extremely unlikely,given that the most luminous source around by far is the quasar itself,and no hint of scattered quasar radiation is seen in the STIS spectrum.
A remaining possibility is jet-induced star formation,as has been suggested by Chatzichristou et al.(1999).This now also seems unlikely because of the age of the stars.An approximate dynamical time scale for the jet can be estimated from its length and the velocity of the
emission-line gas associated with it:τdyn ≈106D kpc v ?1
1000yr.For D =5and v =0.8(see §3),τdyn ≈6×106yr.The apparent stellar age of 3C 48A of 108years is thus much older than the likely age of the radio jet.It is also much older than the likely dynamical time indi-cated by the distance of 3C 48A from the jet if it had been produced by it.If the arc-like structure were to indicate that we are seeing the edge of a “bubble”of star formation caused by the jet,the vector from the point of origin of the bubble to the arc must likely be close to the plane of the sky.Because there is every indica-tion that the host galaxy of 3C 48is quite massive,yet the observed radial velocity range of the stars is quite small (Canalizo &Stockton 2000),stellar motions must
8
be mostly in the plane of the sky.In this case,trans-
verse velocities of at least100km s?1must be expected
for stars in this feature at～5kpc from the quasar.This
means that over108years,we expect space motions of
10kpc,far larger than the～3kpc observed projected
separation between the end of the radio jet and3C48A. Furthermore,Canalizo&Stockton(2000)had found
a general trend of younger average stellar ages as one
moves inward in the3C48host galaxy,with stellar ages
in the inner region of<107years,consistent with a stel-
lar population dominated by a current starburst.3C48A
therefore shows a clear age discontinuity with the stars in
the host galaxy just slightly farther out from the center.
There is suggestive,but not conclusive,evidence for
a velocity discontinuity as well.The two host-galaxy
regions with absorption-line velocities in the study by
Canalizo&Stockton(2000)that are closest to3C48A,
C2and B3(～2′′northeast and east,respectively),have
stellar velocities173±46and170±54higher than that of
3C48A.Velocity gradients for the stars in central region
of the3C48host galaxy appear to be quite low,so this
may be a signi?cant di?erence.
All of this makes the possibility that3C48A is ac-
tually the distorted nucleus of the merging galaxy
(Stockton&Ridgway1991)seem much more attractive.
An age of～108years is not unreasonable for the time
of the previous close passage prior to?nal merging.
It is also similar to the age of star-formation regions
found in the leading edge of the tidal tail(～114Myr;
Canalizo&Stockton2000),which might plausibly date
from the same phase of the encounter.
https://www.doczj.com/doc/1a10812135.html,PARISON WITH PREVIOUS INVESTIGATIONS OF
3C48
The observations reported here are closely related
to two previous spectroscopic studies of3C48and its
host galaxy that have already been mentioned:those
of Chatzichristou et al.(1999)and Canalizo&Stockton
(2000).We have at various points noted comparisons
of our present results with these earlier studies,but it
is worth discussing areas of agreement and disagreement
more systematically.
Chatzichristou et al.(1999)obtained imaging spec-
troscopy of a12′′×8′′?eld around3C48with an IFU
consisting of655optical?bers,each with a diameter
of0.′′4,mounted in the Multi-Object Spectrograph of
the Canada-France-Hawaii telescope.The total exposure
was2700s,and the seeing during the observation was re-
ported to be～0.′′6.The basic conclusions of this study
were that:(1)the broad,blueshifted[O III]emission
noticed in previous observations was actually due to a
combination of the normal narrow-line region at the sys-
temic redshift and a high-velocity component blueshifted
by～580km s?1;(2)this high-velocity component dom-
inates the[O III]pro?le in the center and over a region
at least0.′′6to the north and east of the quasar;(3)the
location and energetics of this high-velocity gas are con-
sistent with its having been accelerated by the radio jet;
(4)the continuum colors of3C48A indicate dominance
by a stellar population younger than107years,with the
star formation likely triggered by the radio jet;and(5)
while much of the emission-line gas appears to be pho-
toionized by the central source,there is some evidence
for additional ionization from shocks.
Canalizo
&Stockton(2000)were mainly concerned
with stellar population distributions and ages in the host galaxy,but also discussed the emission lines present in their spectra.They obtained classical long-slit spectra with the Low-Resolution Imaging Spectrograph on the Keck II telescope,with6di?erent slit positions.They also resolved the nuclear high-velocity component,ob-taining a velocity di?erence from the systemic narrow-line emission of563±40km s?1.While the limita-tions of using slits meant that they could not e?ectively map its distribution,they were able to see that it had a strong velocity gradient over its extent of～0.′′5in a slit through the nucleus at position angle333?.In agreement with Chatzichristou et al.(1999),Canalizo&Stockton (2000)also felt that the general location and velocity of this gas was strong evidence for a scenario in which it has been driven by the radio jet.
Canalizo&Stockton(2000)were not able to say any-thing about the stellar population of3C48A because scattered light from the nucleus completely dominated the spectrum in that region and could not be removed reliably,but they found quite young ages(～4Myr, consistent with ongoing star formation)for regions in the host galaxy they could measure that were just be-yond3C48A.On the basis of the colors reported by Chatzichristou et al.(1999)and on the morphologies of the HST images of3C48A,Canalizo&Stockton(2000) stated,“While it is still possible that this[i.e.,3C48A] may be,in fact,the distorted nuclear regions of the com-panion galaxy in the?nal stages of merger,it now seems more likely that it,too,is related to the interaction of the radio jet with the dense surrounding medium,as sug-gested by Chatzichristou et al.(1999).”
The results we have given here support and re?ne the general conclusions of both of these previous studies re-garding the high-velocity gas.With the higher resolution and better S/N of our deep IFU observations,we have been able to map out the distribution of the extended high-velocity gas in the region within～1′′of the nu-cleus and at several points in its velocity pro?le.These maps,shown in Fig.4,show that this emission peaks 0.′′25almost due north of the quasar,near the base of the jet,and not,as might have been expected,near the point of its obvious de?ection and decollimation,roughly 0.′′5north of the quasar.
Our velocity di?erence between the high-velocity and systemic components of[O III]is491±40km s?1, compared with the previously reported values of563±40km s?1(Canalizo&Stockton2000)and586±15 km s?1(Chatzichristou et al.1999).These di?er-ences are at least partly due to di?erent approaches to calculating di?erential radial velocities from redshifts. Canalizo&Stockton(2000)simply treated the redshifts of the two components each as cosmological redshifts[for which v/c=ln(1+z)]to?nd the di?erence in veloc-ity,and Chatzichristou et al.(1999)apparently did the same.But since the velocity di?erence is actually due bulk motion of material at essentially the same cosmo-logical redshift as the quasar,it is more nearly correct to use the relativistic Doppler formula
?v
(1+z1)2+1?
(1+z2)2?1
9
this approach for the previous determinations,the Canalizo&Stockton(2000)value becomes519±40km s?1,and the Chatzichristou et al.(1999)value becomes 537±15km s?1,both of which are now consistent with our new value.(We also note that it is not clear how Chatzichristou et al.(1999)obtained their standard er-ror of±15km s?1,since their determination is domi-nated by their[O III]λ5007velocity di?erence,which has a standard error of±100km s?1.This small er-ror may,in fact,have been a misprint,since,in their “Conclusions”section,Chatzichristou et al.(1999)give the value as～580±110km s?1.)
Chatzichristou et al.(1999)had previously carried out a calculation of the total kinetic energy of the high-velocity ionized gas and compared this value with the energy available from the radio jet,similar to our cal-culation in§3.The main di?erence in the calculations is that Chatzichristou et al.(1999)assumed a mass for the gas given by Fabian et al.(1987),which happens to agree well with the mass we obtain if the density in the emitting region is close to our approximate upper limit of n e≈100cm?3(this agreement is mostly fortuitous, since Fabian et al.1987used di?erent cosmological pa-rameters and determined the density simply by modeling the[O III]to[O II]emission-line ratio for a single-density medium).Our lower limit to the kinetic energy is about 20%of the value(not intended to be a lower limit)ob-tained by Chatzichristou et al.(1999),so we are roughly consistent,in spite of slightly di?erent assumptions made in the respective calculations.In both cases,the mini-mum energy in the high-velocity gas comprises a signif-icant fraction of the energy of the radio jet,indicating that,if the radio jet is responsible for the current kinetic energy of the gas,the gas is quite capable of a?ecting the dynamics of the jet.However,especially given the fact that most of the emission occurs in a region where the jet seems relatively unperturbed,if the mass(and there-fore the kinetic energy)of the gas should turn out to be signi?cantly larger than the lower limit,it could prove to be di?cult to provide su?cient energy from the radio jet alone.If this were the case,one might be forced to appeal to some other form of coupling the energy output of the quasar to the gas,the evacuation of a channel by the radio jet merely providing a convenient path for the high-velocity gas to escape.However,at this stage,such speculations are premature.
On the question of the origin of3C48A,we feel that our new estimate of the age of the stellar population dominating the continuum light requires a re-evaluation of the previous conclusions.In our view,the balance of the evidence has swung back to the original suggestion of Stockton&Ridgway(1991)that we are seeing the dis-torted nucleus of the merging companion,although with the modi?cation that most of the light is coming from stars that were likely formed from gas driven inwards during the?rst close pass of the interaction,some108 years earlier.
Although we believe that our HST STIS spectrum clearly demonstrates the dominance of stars with ages 108years,without more detailed information we can only speculate on why Chatzichristou et al.(1999) found much younger ages from their estimate of colors for3C48A.It seems possible that scattered light from the quasar may have had a more important in?uence than they had estimated.Chatzichristou et al.(1999) claimed that the scattered contribution to3C48A was ～20%at5100?A and～60%at6900?A.We have made simple models of3C48and3C48A using their quoted seeing of～0.′′6.With very conservative as-sumptions(e.g.,a Gaussian rather than a Mo?at pro-?le for the quasar),we?nd that the scattered contri-bution from the quasar would dominate that of3C48A by at least a factor of2.A more realistic estimate would certainly be much larger.An additional pos-sibility is that,with their rather large aperture,cen-tered1.′′3from the quasar,a bit beyond the center of light of3C48A,at1.′′1,and with ground-based seeing, the light Chatzichristou et al.(1999)measured may have been dominated by the very young stellar populations in this region of the host galaxy(Canalizo&Stockton 2000),rather than light speci?cally from3C48A.Exper-iments with the HST PC F555W image indicate that over half of the light in such an aperture(apart from scattered QSO light)would have come from host galaxy background stars rather than3C48A.
6.SUMMARY AND DISCUSSION
High velocity gas associated with high-redshift radio sources has often been attributed to shocks from,or entrainment by,radio jets(e.g.,Stockton,Ridgway,&Kellogg1996; Sol′o rzano-I?n arrea,Tadhunter,&Bland-Hawthorn2001; Labiano et al.2005;but see also Baum&McCarthy 2000).In most cases,the argument for these mecha-nisms has been largely circumstantial:usually,there are essentially no other plausible sources for the observed velocities.While hardly surprising,it is nevertheless gratifying to?nd that our high-resolution imaging strongly con?rms the positional relation between the high velocity gas and the steep-spectrum radio jet in 3C48found by Chatzichristou et al.(1999).Our main contribution here has been to show more clearly the distribution of the gas as a function of velocity within the pro?le and to show that it appears to be closely associated with the base and inner part of the jet, rather than the region farther from the quasar,where high-resolution radio maps show the most obvious de?ection and decollimation.
In their two-dimensional simulations of the propaga-tion of jets through inhomogeneous media,Saxton et al. (2005)show that it is quite plausible that CSS jets,such as that of3C48,do not require a direct collision with a dense cloud to su?er decollimation and de?ection,as has often been assumed.Instead,the jet,in overpressur-ing the intercloud medium,creates shocks that propagate into and re?ect o?of the dense clouds.These re?ected shocks can then redistribute some of the forward momen-tum of the jet itself into transverse components. Saxton et al.(2005)speci?cally consider the case of the3C48jet.They conclude that their model of a jet progressing through a medium with a rather small?ll-ing factor of dense clouds qualitatively matches the ap-pearance of the3C48jet(modulo possible di?erences a fully three-dimensional model might have from their two-dimensional simulations).The jet is not completely disrupted;it roughly retains its initial direction,but it is de?ected through a small angle,and it becomes decolli-mated into a fan of material.
10
Taking this general picture as a working hypothesis, how does the high-velocity optical emission in3C48?t in?One possibility is that it is due to shock excitation of the gas in the dense clouds responsible for decollimating the radio jet.However,our conclusion that most of the high-velocity emission comes from a region quite close to the quasar,before the jet shows signi?cant disruption, means that the acceleration of the ionized gas is likely not closely coupled with the de?ection of the jet.In addi-tion,it is not clear that the dense clouds themselves will be accelerated to high velocities—whether they are or not depends on their size and mass distribution and the momentum transfered to them by the bow shock of the expanding radio cocoon.Insofar as we have been able to estimate the line ratios in the high-velocity component, they seem to be consistent with photoionization by the quasar continuum,as well as with ionization by shocks (at least with those for which a substantial fraction of the line radiation comes from photoionization of pre-shock material by the thermal continuum of the shock itself). An attractive option is that most of the emission comes from photoionization by the quasar either of ablated ma-terial from small clouds or simply of ambient di?use gas, which likely can be driven to high velocities by the wind generated by the expanding bubble around the jet.
The possibility that3C48A might also be a conse-quence of the radio jet,in the form of jet-induced star formation,now seems rather remote.The age of the stars in this feature is incompatible with jet-induced star for-mation by the current radio jet,and any appeal to pro-duction by a hypothetical previous radio jet would have to explain why the feature remains so coherent and rela-tively close to the radio axis after～108years.Instead, a scenario in which we are seeing the distorted nucleus of the merging companion galaxy seems much more likely. Scharw¨a chter et al.(2004)show that a plausible model of a merger of two equal-mass disk galaxies can both re-produce the approximate appearance of the3C48host and,for a brief period,place the nuclei of the merging galaxies at the separation and approximate position an-gle of the quasar and3C48A.While it would be useful to explore a larger range of parameter space to see if the model can be tuned to give a more exact reproduction of the observed properties,this result is already su?cient to give us con?dence that this picture is basically correct. These results reinforce the conclusion that we are view-ing3C48at a rather rare stage in the life of a quasar and its host galaxy.The age of the radio jet(which pre-sumably also dates the triggering of the current quasar activity)appears to be at most a few106years,and the two nuclei will fully merge on a time scale of～107years.
Support for program#GO-09365was provided by NASA through a grant from the Space Telescope Science Institute,which is operated by the Association of Uni-versities for Research in Astronomy,Inc.,under NASA contract NAS5-26555.We thank the referee for a very careful reading of the paper and for making numerous suggestions that materially improved the?nal version. The authors recognize the very signi?cant cultural role that the summit of Mauna Kea has within the indige-nous Hawaiian community and are grateful to have had the opportunity to conduct observations from it.
REFERENCES
Baum,S.A.,&McCarthy,P.J.2000,AJ,119,2634
Boroson,T.A.,&Oke,J.B.1982
Boroson,T.A.,&Oke,J.B.1984
Boyce,P.J.,Disney,M.J.,&Bleaken,D.G.1999,MNRAS,302, L39
Bruzual,G.,&Charlot,S.1993,ApJ,405,538
Bruzual,G.,&Charlot,S.2003,MNRAS,344,1000
Canalizo,G.,&Stockton,A.2000,ApJ,528,201 Chatzichristou,E.T.,Vanderriest,C.,&Ja?e,W.1999,A&A, 343,407
de Vries,W.H.,O’Dea,C.P.,Baum,S.A.,&Barthel,P.D.1999, ApJ,526,27
Fabian,A.C.,Crawford,C.S.,Johnstone,R.M.,&Thomas,P.
A.1987,MNRAS,228,963
Feng,W.X.,An,T.,Hong,X.Y.,Zhao,J.-H.,Venturi,T.,Shen, Z.-Q.,&Wang,W.H.2005,A&A,434,101
Gelderman,R.,&Whittle,M.1994,ApJS,91,491
Gupta,N.,Srianand,R.,&Saikia,D.J.2005,MNRAS,361,451 Hook,R.N.,Lucy,L.B.,Stockton,A.,&Ridgway,S.E.1994, ST-ECF Newsl.,21,16
Kirhakos,S.,Bahcall,J.N.,Schneider,D.P.,&Kristian,J.1999, ApJ,520,67
Kristian,J.1973,ApJ,179,L61
Labiano,A.et al.2005,A&A,436,493
Matthews et al.1961,Sky&Telescope,21,148Matthews&Sandage1963,ApJ,138,30
Oke,J.B.,et al.1995,PASP,107,375
Saxton,C.J.,Bicknell,G.V.,Sutherland,R.S.,&Midgley,S. 2005,MNRAS,359,781
Scharw¨a chter,J.,Eckart,A.,Pfalzner,S.,Zuther,J.,Krips,M.,& Straubmeier,C.2004,A&A,414,497
Scoville,N.Z.,Padin,S.,Sanders,D.B.,Soifer,B.T.,&Yun,M. S.1993,ApJ,415,L75
Sol′o rzano-I?n arrea,C.,Tadhunder,C.N.,&Bland-Hawthorn,J. 2001,MNRAS,323,965
Stockton,A,&Mackenty,J.W.1987,ApJ,316,584
Stockton,A.,MacKenty,J.W.,Hu,E.M.,&Kim,T.-S.2002, ApJ,572,735
Stockton,A.,&Ridgway,S.E.1991,AJ,102,L131
Stockton,A.,Ridgway,S.E.,&Kellogg,M.1996,AJ,112,902 van Dokkum,P.G.2001,PASP,113,1420
Wampler,E.J.,Robinson,L.B,Burbidge,E.M.,&Baldwin,J.
A.1975,ApJ,198,L49
Wilkinson,P.N.,Tzioumis,A.K.,Benson,J.M.,Walker,R.C., Simon,R.S.,&Kahn,F.D.1991,Nature,352,313
Wink,J.E.,Guilloteau,S.,&Wilson,T.L.1997,A&A,322,427 Zuther,J.,Eckart,A.,Scharw¨a chter,J.,Krips,M.,&Straubmeier, C.2004,A&A,414,919
The way 的用法 Ⅰ常见用法： 1)the way+ that 2)the way + in which（最为正式的用法） 3)the way + 省略（最为自然的用法） 举例：I like the way in which he talks. I like the way that he talks. I like the way he talks. Ⅱ习惯用法： 在当代美国英语中，the way用作为副词的对格，“the way+ 从句”实际上相当于一个状语从句来修饰整个句子。 1)The way =as I am talking to you just the way I’d talk to my own child. He did not do it the way his friends did. Most fruits are naturally sweet and we can eat them just the way they are—all we have to do is to clean and peel them. 2）The way= according to the way/ judging from the way The way you answer the question, you are an excellent student. The way most people look at you, you’d think trash man is a monster. 3）The way =how/ how much No one can imagine the way he missed her. 4）The way =because
【摘要】黄自先生是我国杰出的音乐家，他以艺术歌曲的创作最为代表。而黄自先生特别强调了钢琴伴奏对于艺术歌曲组成的重要性。本文是以黄自先生创作的具有爱国主义和人道主义的艺术歌曲《天伦歌》为研究对象，通过对作品分析，归纳钢琴伴奏的弹奏方法与特点，并总结黄自先生的艺术成就与贡献。 【关键词】艺术歌曲；和声；伴奏织体；弹奏技巧 一、黄自艺术歌曲《天伦歌》的分析 （一）《天伦歌》的人文及创作背景。黄自的艺术歌曲《天伦歌》是一首具有教育意义和人道主义精神的作品。同时，它也具有民族性的特点。这首作品是根据联华公司的影片《天伦》而创作的主题曲，也是我国近代音乐史上第一首为电影谱写的艺术歌曲。作品创作于我国政治动荡、经济不稳定的30年代，这个时期，这种文化思潮冲击着我国各个领域，连音乐艺术领域也未幸免――以《毛毛雨》为代表的黄色歌曲流传广泛，对人民大众，尤其是青少年的不良影响极其深刻，黄自为此担忧，创作了大量艺术修养和文化水平较高的艺术歌曲。《天伦歌》就是在这样的历史背景下创作的，作品以孤儿失去亲人的苦痛为起点，发展到人民的发愤图强，最后升华到博爱、奋起的民族志向，对青少年的爱国主义教育有着重要的影响。 （二）《天伦歌》曲式与和声。《天伦歌》是并列三部曲式，为a+b+c，最后扩充并达到全曲的高潮。作品中引子和coda所使用的音乐材料相同，前后呼应，合头合尾。这首艺术歌曲结构规整，乐句进行的较为清晰，所使用的节拍韵律符合歌词的特点，如三连音紧密连接，为突出歌词中号召的力量等。 和声上，充分体现了中西方作曲技法融合的创作特性。使用了很多七和弦。其中，一部分是西方的和声，一部分是将我国传统的五声调式中的五个音纵向的结合，构成五声性和弦。与前两首作品相比，《天伦歌》的民族性因素增强，这也与它本身的歌词内容和要弘扬的爱国主义精神相对应。 （三）《天伦歌》的伴奏织体分析。《天伦歌》的前奏使用了a段进唱的旋律发展而来的，具有五声调性特点，增添了民族性的色彩。在作品的第10小节转调入近关系调，调性的转换使歌曲增添抒情的情绪。这时的伴奏加强和弦力度，采用切分节奏，节拍重音突出，与a段形成强弱的明显对比，突出悲壮情绪。 c段的伴奏采用进行曲的风格，右手以和弦为主，表现铿锵有力的进行。右手为上行进行，把全曲推向最高潮。左手仍以柱式和弦为主，保持节奏稳定。在作品的扩展乐段，左手的节拍低音上行与右手的八度和弦与音程对应，推动音乐朝向宏伟、壮丽的方向进行。coda 处，与引子材料相同，首尾呼应。 二、《天伦歌》实践研究 《天伦歌》是具有很强民族性因素的作品。所谓民族性，体现在所使用的五声性和声、传统歌词韵律以及歌曲段落发展等方面上。 作品的整个发展过程可以用伤感――悲壮――兴奋――宏达四个过程来表述。在钢琴伴奏弹奏的时候，要以演唱者的歌唱状态为中心，选择合适的伴奏音量、音色和音质来配合，做到对演唱者的演唱同步，并起到连接、补充、修饰等辅助作用。 作品分为三段，即a+b+c+扩充段落。第一段以五声音阶的进行为主，表现儿童失去父母的悲伤和痛苦，前奏进入时要弹奏的使用稍凄楚的音色，左手低音重复进行，在弹奏完第一个低音后，要迅速的找到下一个跨音区的音符；右手弹奏的要有棱角，在前奏结束的时候第四小节的t方向的延音处，要给演唱者留有准备。演唱者进入后，左手整体的踏板使用的要连贯。随着作品发展，伴奏与旋律声部出现轮唱的形式，要弹奏的流动性强，稍突出一些。后以mf力度出现的具有转调性质的琶音奏法，要弹奏的如流水般连贯。在重复段落，即“小
The way的用法及其含义（二） 二、the way在句中的语法作用 the way在句中可以作主语、宾语或表语： 1.作主语 The way you are doing it is completely crazy.你这个干法简直发疯。 The way she puts on that accent really irritates me. 她故意操那种口音的样子实在令我恼火。The way she behaved towards him was utterly ruthless. 她对待他真是无情至极。 Words are important, but the way a person stands, folds his or her arms or moves his or her hands can also give us information about his or her feelings. 言语固然重要,但人的站姿,抱臂的方式和手势也回告诉我们他(她)的情感。 2.作宾语 I hate the way she stared at me.我讨厌她盯我看的样子。 We like the way that her hair hangs down.我们喜欢她的头发笔直地垂下来。 You could tell she was foreign by the way she was dressed. 从她的穿著就可以看出她是外国人。 She could not hide her amusement at the way he was dancing. 她见他跳舞的姿势，忍俊不禁。 3.作表语 This is the way the accident happened.这就是事故如何发生的。 Believe it or not, that's the way it is. 信不信由你, 反正事情就是这样。 That's the way I look at it, too. 我也是这么想。 That was the way minority nationalities were treated in old China. 那就是少数民族在旧中
我国艺术歌曲钢琴伴奏-精 2020-12-12 【关键字】传统、作风、整体、现代、快速、统一、发展、建立、了解、研究、特点、突出、关键、内涵、情绪、力量、地位、需要、氛围、重点、需求、特色、作用、结构、关系、增强、塑造、借鉴、把握、形成、丰富、满足、帮助、发挥、提高、内心 【摘要】艺术歌曲中，伴奏、旋律、诗歌三者是不可分割的重 要因素，它们三个共同构成一个统一体，伴奏声部与声乐演唱处于 同样的重要地位。形成了人声与器乐的巧妙的结合，即钢琴和歌唱 的二重奏。钢琴部分的音乐使歌曲紧密的联系起来，组成形象变化 丰富而且不中断的套曲，把音乐表达的淋漓尽致。 【关键词】艺术歌曲；钢琴伴奏；中国艺术歌曲 艺术歌曲中，钢琴伴奏不是简单、辅助的衬托，而是根据音乐 作品的内容为表现音乐形象的需要来进行创作的重要部分。准确了 解钢琴伴奏与艺术歌曲之间的关系,深层次地了解其钢琴伴奏的风 格特点,能帮助我们更为准确地把握钢琴伴奏在艺术歌曲中的作用 和地位，从而在演奏实践中为歌曲的演唱起到更好的烘托作用。 一、中国艺术歌曲与钢琴伴奏 “中西结合”是中国艺术歌曲中钢琴伴奏的主要特征之一，作 曲家们将西洋作曲技法同中国的传统文化相结合，从开始的借鉴古 典乐派和浪漫主义时期的创作风格，到尝试接近民族乐派及印象主 义乐派的风格，在融入中国风格的钢琴伴奏写作，都是对中国艺术 歌曲中钢琴写作技法的进一步尝试和提高。也为后来的艺术歌曲写 作提供了更多宝贵的经验，在长期发展中，我国艺术歌曲的钢琴伴 奏也逐渐呈现出多姿多彩的音乐风格和特色。中国艺术歌曲的钢琴
写作中，不可忽略的是钢琴伴奏织体的作用，因此作曲家们通常都以丰富的伴奏织体来烘托歌曲的意境，铺垫音乐背景，增强音乐感染力。和声织体，复调织体都在许多作品中使用，较为常见的是综合织体。这些不同的伴奏织体的歌曲，极大限度的发挥了钢琴的艺术表现力，起到了渲染歌曲氛围，揭示内心情感，塑造歌曲背景的重要作用。钢琴伴奏成为整体乐思不可缺少的部分。优秀的钢琴伴奏织体，对发掘歌曲内涵，表现音乐形象，构架诗词与音乐之间的桥梁等方面具有很大的意义。在不断发展和探索中，也将许多伴奏织体使用得非常娴熟精确。 二、青主艺术歌曲《我住长江头》中钢琴伴奏的特点 《我住长江头》原词模仿民歌风格，抒写一个女子怀念其爱人的深情。青主以清新悠远的音乐体现了原词的意境，而又别有寄寓。歌调悠长，但有别于民间的山歌小曲；句尾经常出现下行或向上的拖腔，听起来更接近于吟哦古诗的意味，却又比吟诗更具激情。钢琴伴奏以江水般流动的音型贯穿全曲，衬托着气息宽广的歌唱，象征着绵绵不断的情思。由于运用了自然调式的旋律与和声，显得自由舒畅，富于浪漫气息，并具有民族风味。最有新意的是，歌曲突破了“卜算子”词牌双调上、下两阕一般应取平行反复结构的惯例，而把下阕单独反复了三次，并且一次比一次激动，最后在全曲的高音区以ff结束。这样的处理突出了思念之情的真切和执著，并具有单纯的情歌所没有的昂奋力量。这是因为作者当年是大革命的参加者，正被反动派通缉，才不得不以破格的音乐处理，假借古代的
定冠词the的用法： 定冠词the与指示代词this ,that同源,有“那(这)个”的意思,但较弱,可以和一个名词连用,来表示某个或某些特定的人或东西. (1)特指双方都明白的人或物 Take the medicine.把药吃了. (2)上文提到过的人或事 He bought a house.他买了幢房子. I've been to the house.我去过那幢房子. (3)指世界上独一无二的事物 the sun ,the sky ,the moon, the earth (4)单数名词连用表示一类事物 the dollar 美元 the fox 狐狸 或与形容词或分词连用,表示一类人 the rich 富人 the living 生者 (5)用在序数词和形容词最高级,及形容词等前面 Where do you live?你住在哪? I live on the second floor.我住在二楼. That's the very thing I've been looking for.那正是我要找的东西. (6)与复数名词连用,指整个群体 They are the teachers of this school.(指全体教师) They are teachers of this school.(指部分教师) (7)表示所有,相当于物主代词,用在表示身体部位的名词前 She caught me by the arm.她抓住了我的手臂. (8)用在某些有普通名词构成的国家名称,机关团体,阶级等专有名词前 the People's Republic of China 中华人民共和国 the United States 美国 (9)用在表示乐器的名词前 She plays the piano.她会弹钢琴. (10)用在姓氏的复数名词之前,表示一家人 the Greens 格林一家人(或格林夫妇) (11)用在惯用语中 in the day, in the morning... the day before yesterday, the next morning... in the sky... in the dark... in the end... on the whole, by the way...
“tｈｅwａｙ+从句”结构的意义及用法 首先让我们来看下面这个句子: Ｒead the foｌloｗｉnｇpassagｅａnd talkａbout ｉt wi ｔh your classmaｔes．Try tｏｔeｌl whaｔyｏu thiｎk ｏf Tom aｎd ｏｆｔhe ｗay the chiｌｄrenｔrｅated ｈim. 在这个句子中，ｔhe waｙ是先行词,后面是省略了关系副词that或in whｉch的定语从句。 下面我们将叙述“the ｗaｙ+从句”结构的用法。 1.tｈe wａy之后，引导定语从句的关系词是tｈat而不是hoｗ,因此，<<现代英语惯用法词典＞＞中所给出的下面两个句子是错误的：Ｔhｉs is ｔｈeｗayｈowｉtｈａppened. This is the way how he ａlwａｙs treats me. 2．在正式语体中,thaｔ可被in which所代替;在非正式语体中，ｔhat则往往省略。由此我们得到theｗay后接定语从句时的三种模式：1) tｈe ｗaｙ＋ｔhａt-从句２）the way +ｉn whiｃh－从句3) the ｗay +从句 例如：Ｔｈe way(in whiｃh ，thａt) ｔhｅｓｅｃomｒade ｓloｏｋａｔｐrobｌems is wrong．这些同志看问题的方法
不对。 Ｔｈｅｗａy(that ,ｉn ｗhiｃh)yoｕ’ｒe doinｇit is comple ｔeｌy crａzy.你这么个干法,简直发疯。 Wｅａdmiｒｅd him for thｅｗay ｉｎｗhｉch he fａｃeｓdiｆficultieｓ． Waｌlａｃe ａｎd Ｄarwiｎｇreed ｏn the way ｉｎwhi ｃh ｄｉfｆｅrｅnt forms ｏf life had ｂegｕn.华莱士和达尔文对不同类型的生物是如何起源的持相同的观点。 Thｉs is ｔｈe ｗaｙ（tｈａｔ) hｅdｉd it. I lｉkeｄｔhe waｙ(ｔhat) ｓｈeｏｒganized ｔhe ｍeetｉng． 3.theｗay(tｈat)有时可以与hｏw(作“如何”解）通用。例如： That’s tｈe ｗaｙ(tｈaｔ) shｅspoke. = Tｈat’s how shｅspoke.
表示“方式”、“方法”，注意以下用法： 1.表示用某种方法或按某种方式，通常用介词in(此介词有时可省略)。如： Do it (in) your own way. 按你自己的方法做吧。 Please do not talk (in) that way. 请不要那样说。 2.表示做某事的方式或方法，其后可接不定式或of doing sth。 如： It’s the best way of studying [to study] English. 这是学习英语的最好方法。 There are different ways to do [of doing] it. 做这事有不同的办法。 3.其后通常可直接跟一个定语从句(不用任何引导词)，也可跟由that 或in which 引导的定语从句，但是其后的从句不能由how 来引导。如： 我不喜欢他说话的态度。 正：I don’t like the way he spoke. 正：I don’t like the way that he spoke. 正：I don’t like the way in which he spoke. 误：I don’t like the way how he spoke. 4.注意以下各句the way 的用法： That’s the way (=how) he spoke. 那就是他说话的方式。 Nobody else loves you the way(=as) I do. 没有人像我这样爱你。 The way (=According as) you are studying now, you won’tmake much progress. 根据你现在学习情况来看，你不会有多大的进步。 2007年陕西省高考英语中有这样一道单项填空题： ——I think he is taking an active part insocial work. ——I agree with you_____. A、in a way B、on the way C、by the way D、in the way 此题答案选A。要想弄清为什么选A，而不选其他几项，则要弄清选项中含way的四个短语的不同意义和用法，下面我们就对此作一归纳和小结。 一、in a way的用法 表示：在一定程度上，从某方面说。如： In a way he was right.在某种程度上他是对的。注：in a way也可说成in one way。 二、on the way的用法 1、表示：即将来(去)，就要来(去)。如： Spring is on the way.春天快到了。 I'd better be on my way soon.我最好还是快点儿走。 Radio forecasts said a sixth-grade wind was on the way.无线电预报说将有六级大风。 2、表示：在路上，在行进中。如： He stopped for breakfast on the way.他中途停下吃早点。 We had some good laughs on the way.我们在路上好好笑了一阵子。 3、表示：(婴儿)尚未出生。如： She has two children with another one on the way.她有两个孩子，现在还怀着一个。 She's got five children，and another one is on the way.她已经有5个孩子了，另一个又快生了。 三、by the way的用法
The way的用法及其含义（一） 有这样一个句子：In 1770 the room was completed the way she wanted. 1770年，这间琥珀屋按照她的要求完成了。 the way在句中的语法作用是什么？其意义如何？在阅读时，学生经常会碰到一些含有the way 的句子，如：No one knows the way he invented the machine. He did not do the experiment the way his teacher told him.等等。他们对the way 的用法和含义比较模糊。在这几个句子中，the way之后的部分都是定语从句。第一句的意思是，“没人知道他是怎样发明这台机器的。”the way的意思相当于how；第二句的意思是，“他没有按照老师说的那样做实验。”the way 的意思相当于as。在In 1770 the room was completed the way she wanted.这句话中，the way也是as的含义。随着现代英语的发展，the way的用法已越来越普遍了。下面，我们从the way的语法作用和意义等方面做一考查和分析： 一、the way作先行词，后接定语从句 以下3种表达都是正确的。例如：“我喜欢她笑的样子。” 1. the way+ in which +从句 I like the way in which she smiles. 2. the way+ that +从句 I like the way that she smiles. 3. the way + 从句(省略了in which或that) I like the way she smiles. 又如：“火灾如何发生的，有好几种说法。” 1. There were several theories about the way in which the fire started. 2. There were several theories about the way that the fire started.
way 的用法 【语境展示】 1. Now I’ll show you how to do the experiment in a different way. 下面我来演示如何用一种不同的方法做这个实验。 2. The teacher had a strange way to make his classes lively and interesting. 这位老师有种奇怪的办法让他的课生动有趣。 3. Can you tell me the best way of working out this problem? 你能告诉我算出这道题的最好方法吗？ 4. I don’t know the way (that / in which) he helped her out. 我不知道他用什么方法帮助她摆脱困境的。 5. The way (that / which) he talked about to solve the problem was difficult to understand. 他所谈到的解决这个问题的方法难以理解。 6. I don’t like the way that / which is being widely used for saving water. 我不喜欢这种正在被广泛使用的节水方法。 7. They did not do it the way we do now. 他们以前的做法和我们现在不一样。 【归纳总结】 ●way作“方法，方式”讲时，如表示“以……方式”，前面常加介词in。如例1； ●way作“方法，方式”讲时，其后可接不定式to do sth.，也可接of doing sth. 作定语，表示做某事的方法。如例2，例3；
t h e-w a y-的用法
The way 的用法 "the way+从句"结构在英语教科书中出现的频率较高, the way 是先行词, 其后是定语从句.它有三种表达形式:1) the way+that 2)the way+ in which 3)the way + 从句(省略了that或in which),在通常情况下, 用in which 引导的定语从句最为正式,用that的次之,而省略了关系代词that 或 in which 的, 反而显得更自然,最为常用.如下面三句话所示,其意义相同. I like the way in which he talks. I like the way that he talks. I like the way he talks. 一.在当代美国英语中,the way用作为副词的对格,"the way+从句"实际上相当于一个状语从句来修饰全句. the way=as 1)I'm talking to you just the way I'd talk to a boy of my own. 我和你说话就象和自己孩子说话一样. 2)He did not do it the way his friend did. 他没有象他朋友那样去做此事. 3)Most fruits are naturally sweet and we can eat them just the way they are ----all we have to do is clean or peel them . 大部分水果天然甜润,可以直接食用,我们只需要把他们清洗一下或去皮.
way的用法总结大全 way的用法你知道多少，今天给大家带来way的用法，希望能够帮助到大家，下面就和大家分享，来欣赏一下吧。 way的用法总结大全 way的意思 n. 道路,方法,方向,某方面 adv. 远远地，大大地 way用法 way可以用作名词 way的基本意思是“路,道,街,径”,一般用来指具体的“路,道路”,也可指通向某地的“方向”“路线”或做某事所采用的手段,即“方式,方法”。way还可指“习俗,作风”“距离”“附近,周围”“某方面”等。 way作“方法,方式,手段”解时,前面常加介词in。如果way前有this, that等限定词,介词可省略,但如果放在句首,介词则不可省略。
way作“方式,方法”解时,其后可接of v -ing或to- v 作定语,也可接定语从句,引导从句的关系代词或关系副词常可省略。 way用作名词的用法例句 I am on my way to the grocery store.我正在去杂货店的路上。 We lost the way in the dark.我们在黑夜中迷路了。 He asked me the way to London.他问我去伦敦的路。 way可以用作副词 way用作副词时意思是“远远地,大大地”,通常指在程度或距离上有一定的差距。 way back表示“很久以前”。 way用作副词的用法例句 It seems like Im always way too busy with work.我工作总是太忙了。 His ideas were way ahead of his time.他的思想远远超越了他那个时代。 She finished the race way ahead of the other runners.她第一个跑到终点,远远领先于其他选手。 way用法例句
t h e_w a y的用法大全
The way 在the way+从句中, the way 是先行词, 其后是定语从句.它有三种表达形式:1) the way+that 2)the way+ in which 3)the way + 从句(省略了that或in which),在通常情况下, 用in which 引导的定语从句最为正式,用that的次之,而省略了关系代词that 或 in which 的, 反而显得更自然,最为常用.如下面三句话所示,其意义相同. I like the way in which he talks. I like the way that he talks. I like the way he talks. 如果怕弄混淆，下面的可以不看了 另外，在当代美国英语中,the way用作为副词的对格,"the way+从句"实际上相当于一个状语从句来修饰全句. the way=as 1)I'm talking to you just the way I'd talk to a boy of my own. 我和你说话就象和自己孩子说话一样. 2)He did not do it the way his friend did. 他没有象他朋友那样去做此事. 3)Most fruits are naturally sweet and we can eat them just the way they are ----all we have to do is clean or peel them . 大部分水果天然甜润,可以直接食用,我们只需要把他们清洗一下或去皮. the way=according to the way/judging from the way 4)The way you answer the qquestions, you must be an excellent student. 从你回答就知道,你是一个优秀的学生. 5)The way most people look at you, you'd think a trashman was a monster. 从大多数人看你的目光中,你就知道垃圾工在他们眼里是怪物. the way=how/how much 6)I know where you are from by the way you pronounce my name. 从你叫我名字的音调中,我知道你哪里人. 7)No one can imaine the way he misses her. 人们很想想象他是多么想念她. the way=because 8) No wonder that girls looks down upon me, the way you encourage her. 难怪那姑娘看不起我, 原来是你怂恿的
The way 的用法 "the way+从句"结构在英语教科书中出现的频率较高, the way 是先行词, 其后是定语从句.它有三种表达形式:1) the way+that 2)the way+ in which 3)the way + 从句(省略了that或in which),在通常情况下, 用in which 引导的定语从句最为正式,用that的次之,而省略了关系代词that 或in which 的, 反而显得更自然,最为常用.如下面三句话所示,其意义相同. I like the way in which he talks. I like the way that he talks. I like the way he talks. 一.在当代美国英语中,the way用作为副词的对格,"the way+从句"实际上相当于一个状语从句来修饰全句. the way=as 1)I'm talking to you just the way I'd talk to a boy of my own. 我和你说话就象和自己孩子说话一样. 2)He did not do it the way his friend did. 他没有象他朋友那样去做此事. 3)Most fruits are naturally sweet and we can eat them just the way they are ----all we have to do is clean or peel them . 大部分水果天然甜润,可以直接食用,我们只需要把他们清洗一下或去皮.
the way=according to the way/judging from the way 4)The way you answer the qquestions, you must be an excellent student. 从你回答就知道,你是一个优秀的学生. 5)The way most people look at you, you'd think a trashman was a monster. 从大多数人看你的目光中,你就知道垃圾工在他们眼里是怪物. the way=how/how much 6)I know where you are from by the way you pronounce my name. 从你叫我名字的音调中,我知道你哪里人. 7)No one can imaine the way he misses her. 人们很想想象他是多么想念她. the way=because 8) No wonder that girls looks down upon me, the way you encourage her. 难怪那姑娘看不起我, 原来是你怂恿的 the way =while/when(表示对比) 9)From that day on, they walked into the classroom carrying defeat on their shoulders the way other students carried textbooks under their arms. 从那天起,其他同学是夹着书本来上课,而他们却带着"失败"的思想负担来上课.
The way的用法及其含义（三） 三、the way的语义 1. the way=as（像） Please do it the way I’ve told you.请按照我告诉你的那样做。 I'm talking to you just the way I'd talk to a boy of my own.我和你说话就像和自己孩子说话一样。 Plant need water the way they need sun light. 植物需要水就像它们需要阳光一样。 2. the way=how（怎样，多么） No one can imagine the way he misses her.没人能够想象出他是多么想念她！ I want to find out the way a volcano has formed.我想弄清楚火山是怎样形成的。 He was filled with anger at the way he had been treated.他因遭受如此待遇而怒火满腔。That’s the way she speaks.她就是那样讲话的。 3. the way=according as （根据） The way you answer the questions, you must be an excellent student.从你回答问题来看，你一定是名优秀的学生。 The way most people look at you, you'd think a trash man was a monster.从大多数人看你的目光中,你就知道垃圾工在他们眼里是怪物。 The way I look at it, it’s not what you do that matters so much.依我看，重要的并不是你做什么。 I might have been his son the way he talked.根据他说话的样子，好像我是他的儿子一样。One would think these men owned the earth the way they behave.他们这样行动，人家竟会以为他们是地球的主人。
一．Way：“方式”、“方法” 1.表示用某种方法或按某种方式 Do it (in) your own way. Please do not talk (in) that way. 2.表示做某事的方式或方法 It’s the best way of studying [to study] English.。 There are different ways to do [of doing] it. 3.其后通常可直接跟一个定语从句(不用任何引导词)，也可跟由that 或in which 引导的定语从句 正：I don’t like the way he spoke. I don’t like the way that he spoke. I don’t like the way in which he spoke.误：I don’t like the way how he spoke. 4. the way 的从句 That’s the way (=how) he spoke. I know where you are from by the way you pronounce my name. That was the way minority nationalities were treated in old China. Nobody else loves you the way(=as) I do. He did not do it the way his friend did. 二．固定搭配 1. In a/one way：In a way he was right. 2. In the way /get in one’s way I'm afraid your car is in the way， If you are not going to help，at least don't get in the way. You'll have to move－you're in my way. 3. in no way Theory can in no way be separated from practice. 4. On the way (to……) Let’s wait a few moments. He is on the way Spring is on the way. Radio forecasts said a sixth-grade wind was on the way. She has two children with another one on the way. 5. By the way By the way，do you know where Mary lives? 6. By way of Learn English by way of watching US TV series. 8. under way 1. Elbow one’s way He elbowed his way to the front of the queue. 2. shoulder one’s way 3. feel one‘s way 摸索着向前走；We couldn’t see anything in the cave, so we had to feel our way out 4. fight/force one’s way 突破。。。而前进The surrounded soldiers fought their way out. 5.. push/thrust one‘s way（在人群中）挤出一条路He pushed his way through the crowd. 6. wind one’s way 蜿蜒前进 7. lead the way 带路，领路；示范 8. lose one‘s way 迷失方向 9. clear the way 排除障碍，开路迷路 10. make one’s way 前进，行进The team slowly made their way through the jungle.
在the way+从句中, the way 是先行词, 其后是定语从句.它有三种表达形式:1) the way+that 2)the way+ in which 3)the way + 从句(省略了that或in which),在通常情况下, 用in which 引导的定语从句最为正式,用that的次之,而省略了关系代词that 或in which 的, 反而显得更自然,最为常用.如下面三句话所示,其意义相同. I like the way in which he talks. I like the way that he talks. I like the way he talks. 如果怕弄混淆，下面的可以不看了 另外，在当代美国英语中,the way用作为副词的对格,"the way+从句"实际上相当于一个状语从句来修饰全句. the way=as 1)I'm talking to you just the way I'd talk to a boy of my own. 我和你说话就象和自己孩子说话一样. 2)He did not do it the way his friend did. 他没有象他朋友那样去做此事. 3)Most fruits are naturally sweet and we can eat them just the way they are ----all we have to do is clean or peel them . 大部分水果天然甜润,可以直接食用,我们只需要把他们清洗一下或去皮. the way=according to the way/judging from the way 4)The way you answer the qquestions, you must be an excellent student. 从你回答就知道,你是一个优秀的学生. 5)The way most people look at you, you'd think a trashman was a monster. 从大多数人看你的目光中,你就知道垃圾工在他们眼里是怪物. the way=how/how much 6)I know where you are from by the way you pronounce my name. 从你叫我名字的音调中,我知道你哪里人. 7)No one can imaine the way he misses her. 人们很想想象他是多么想念她. the way=because 8) No wonder that girls looks down upon me, the way you encourage her. 难怪那姑娘看不起我, 原来是你怂恿的 the way =while/when(表示对比) 9)From that day on, they walked into the classroom carrying defeat on their shoulders the way other students carried textbooks under their arms.
“the way+从句”结构的意义及用法 首先让我们来看下面这个句子： Read the following passage and talk about it with your classmates. Try to tell what you think of Tom and of the way the children treated him. 在这个句子中，the way是先行词，后面是省略了关系副词that 或in which的定语从句。 下面我们将叙述“the way+从句”结构的用法。 1．the way之后，引导定语从句的关系词是that而不是how,因此，<<现代英语惯用法词典>>中所给出的下面两个句子是错误的：This is the way how it happened. This is the way how he always treats me. 2. 在正式语体中，that可被in which所代替；在非正式语体中，that则往往省略。由此我们得到the way后接定语从句时的三种模式：1) the way +that-从句2) the way +in which-从句3) the way +从句 例如：The way(in which ,that) these comrades look at problems is wrong.这些同志看问题的方法不对。
The way(that ,in which)you’re doing it is completely crazy.你这么个干法，简直发疯。 We admired him for the way in which he faces difficulties. Wallace and Darwin greed on the way in which different forms of life had begun.华莱士和达尔文对不同类型的生物是如何起源的持相同的观点。 This is the way (that) he did it. I liked the way (that) she organized the meeting. 3.the way(that)有时可以与how(作“如何”解)通用。例如： That’s the way (that) she spoke. = That’s how she spoke. I should like to know the way/how you learned to master the fundamental technique within so short a time. 4．the way的其它用法：以上我们讲的都是用作先行词的the way，下面我们将叙述它的一些用法。