J/ApJ/858/60 z∼0.8 quiescent galaxy kinematics from LEGA-C (Bezanson+, 2018)
Spatially resolved stellar kinematics from LEGA-C: increased rotational support
in z∼0.8 quiescent galaxies.
Bezanson R., van der Wel A., Pacifici C., Noeske K., Barisic I., Bell E.F.,
Brammer G.B., Calhau J., Chauke P., van Dokkum P., Franx M., Gallazzi A.,
van Houdt J., Labbe I., Maseda M.V., Munos-Mateos J.C., Muzzin A., van de
Sande J., Sobral D., Straatman C., Wu P.-F.
<Astrophys. J., 858, 60 (2018)>
=2018ApJ...858...60B 2018ApJ...858...60B
ADC_Keywords: Galaxies, spectra; Redshifts; Morphology; Velocity dispersion;
Rotational velocities
Keywords: galaxies: elliptical and lenticular, cD; galaxies: evolution;
galaxies: high-redshift; galaxies: kinematics and dynamics;
galaxies: structure
Abstract:
We present stellar rotation curves and velocity dispersion profiles
for 104 quiescent galaxies at z=0.6-1 from the Large Early Galaxy
Astrophysics Census (LEGA-C) spectroscopic survey. Rotation is
typically probed across 10-20kpc, or to an average of 2.7Re. Combined
with central stellar velocity dispersions (σ0) this provides the
first determination of the dynamical state of a sample selected by a
lack of star formation activity at large lookback time. The most
massive galaxies (M*>2x1011M☉) generally show no or little
rotation measured at 5 kpc (|V5|/σ0<0.2 in eight of ten
cases), while ∼64% of less massive galaxies show significant rotation.
This is reminiscent of local fast- and slow- rotating ellipticals and
implies that low- and high-redshift quiescent galaxies have
qualitatively similar dynamical structures. We compare
|V5|/σ0 distributions at z∼0.8 and the present day by
re-binning and smoothing the kinematic maps of 91 low-redshift
quiescent galaxies from the Calar Alto Legacy Integral Field Area
(CALIFA) survey and find evidence for a decrease in rotational support
since z∼1. This result is especially strong when galaxies are compared
at fixed velocity dispersion; if velocity dispersion does not evolve
for individual galaxies then the rotational velocity at 5kpc was an
average of 94±22% higher in z∼0.8 quiescent galaxies than today.
Considering that the number of quiescent galaxies grows with time and
that new additions to the population descend from rotationally
supported star-forming galaxies, our results imply that quiescent
galaxies must lose angular momentum between z∼1 and the present,
presumably through dissipationless merging, and/or that the mechanism
that transforms star-forming galaxies also reduces their rotational
support.
Description:
The spectroscopic data included in this analysis are drawn from the
first year data release of the LEGA-C survey (van der Wel+
2016ApJS..223...29V 2016ApJS..223...29V). This project is a 128 night ESO Public
Spectroscopic survey of massive galaxies at 0.6<z<1.0 in the COSMOS
field using VIMOS on the VLT.
The defining, unique aspect of the LEGA-C spectra is the deep 20hr
long integration at a resolution of R=2500 in the wavelength range
∼6300-8800Å.
Additional ancillary data are available for the LEGA-C sample in the
COSMOS field.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 110 104 Properties of quiescent galaxies in the LEGA-C sample
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See also:
J/A+AS/141/371 : Low-mass stars evolutionary tracks (Girardi+, 2000)
J/MNRAS/371/703 : MILES library of empirical spectra (Sanchez-Blazquez+, 2006)
J/ApJ/665/1067 : Velocities in Cl 0024+16 and MS 0451-03 (Moran+, 2007)
J/MNRAS/382/109 : Massive galaxies in Extended Groth Strip (Trujillo+, 2007)
J/ApJ/706/1364 : SINS survey of high-redshift gal. (Forster Schreiber+, 2009)
J/ApJ/720/723 : Compact galaxies in the local universe (Taylor+, 2010)
J/MNRAS/414/888 : ATLAS3D project. III. (Emsellem+, 2011)
J/A+A/544/A156 : UltraVISTA Catalogue Release DR1 (McCracken+, 2012)
J/ApJS/203/24 : Structural param. of gal. in CANDELS (van der Wel+, 2012)
J/ApJS/206/8 : COSMOS/UltraVISTA Ks-selected catalogs v4.1 (Muzzin+, 2013)
J/ApJ/777/18 : Stellar mass functions of galaxies to z=4 (Muzzin+, 2013)
J/ApJ/762/77 : PM2GC mass-limited sample surface photom. (Poggianti+, 2013)
J/ApJ/768/74 : PHIBSS: CO obs. of star-forming galaxies (Tacconi+, 2013)
J/ApJ/771/85 : Dynamical masses of z∼2 quiescent gal. (van de Sande+, 2013)
J/MNRAS/454/2050 : SAMI Pilot Survey (Fogarty+, 2015)
J/MNRAS/448/3484 : ATLAS3D Project. XXX (McDermid+, 2015)
J/A+A/594/A36 : CALIFA Survey DR3 list of galaxies (Sanchez+, 2016)
J/ApJ/830/14 : SIGMA: Keck spectra of z∼2 gal. in CANDELS (Simons+, 2016)
J/A+A/597/A48 : Stellar kinematics in CALIFA survey (Falcon-Barroso+, 2017)
J/A+A/598/A32 : 2D decomposition of CALIFA galaxies (Mendez-Abreu+, 2017)
J/ApJ/835/104 : SAMI Galaxy Survey: rotators classif. (van de Sande+, 2017)
J/ApJS/239/27 : LEGA-C DR2: galaxies in the COSMOS field (Straatman+, 2018)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- ID [80755/240174] Muzzin+ (2013, J/ApJS/206/8)
UltraVISTA catalog (1)
8- 13 F6.4 --- zspec [0.5/1.1] Spectroscopic redshift
15- 18 F4.1 [Msun] logM [10.2/11.6] log_10 Stellar (Mass/M_sun) (2)
20- 23 F4.2 arcsec Re [0.07/2.6] Effective radius
along the major axis
25- 28 F4.2 arcsec e_Re [0/0.04] Uncertainty in Re
30- 33 F4.2 --- q [0.2/1] Projected axis ratio, b/a
35- 38 F4.2 --- e_q [0/0.01] Uncertainty in q
40- 45 F6.2 deg PA [-45/45] Major axis position angle,
east of north
47- 50 F4.2 deg e_PA [0.1/1.5] Uncertainty in PA
52- 55 F4.2 --- n [0.5/6] Sersic Index
57- 60 F4.2 --- e_n [0.01/0.3] Uncertainty in n
62- 67 F6.1 km/s V5 [-164/154] Average line-of-sight
rot. velocity at 5kpc
69- 73 F5.1 km/s e_V5 [1/23]?=-99 Uncertainty in V5
75- 80 F6.1 km/s VRe [-186.1/219] Average line-of sight
rot. velocity at Re
82- 86 F5.1 km/s e_VRe [0.4/19]?=-99 Uncertainty in VRe
88- 93 F6.1 km/s Vmax [-244/238] Average line-of sight
rot. velocity at the maximum extent of
the rotation curve
95- 99 F5.1 km/s e_Vmax [0.8/35.1]?=-99 Uncertainty in Vmax
101-105 F5.1 km/s sigma0 [96/384] Velocity dispersion in
the central pixel
107-110 F4.1 km/s e_sigma0 [2.7/24.1] Uncertainty in sigma0
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Note (1): This table includes measured properties of the galaxies included
in this sample from the year one LEGA-C dataset. All galaxies included
in this table are well-aligned with the N-S VIMOS slits (|PA|<45
degrees), quiescent based on Muzzin+ (2013, J/ApJ/777/18) U-V and
V-J rest-frame color cuts, have reliable morphological parameters
measured from ACS F814 images, and represent single Virialized systems.
Note (2): Assuming a Chabrier (2003PASP..115..763C 2003PASP..115..763C) IMF.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 18-Mar-2019