J/ApJ/754/67 Longslit spectroscopy of local bulges (Fabricius+, 2012)
Kinematic signatures of bulges correlate with bulge morphologies and
Sersic index.
Fabricius M.H., Saglia R.P., Fisher D.B., Drory N., Bender R., Hopp U.
<Astrophys. J., 754, 67 (2012)>
=2012ApJ...754...67F 2012ApJ...754...67F
ADC_Keywords: Galaxy catalogs ; Radial velocities ; Morphology
Keywords: galaxies: bulges - galaxies: formation - galaxies: general -
galaxies: kinematics and dynamics - galaxies: photometry -
galaxies: spiral - galaxies: structure
Abstract:
We use the Marcario Low Resolution Spectrograph (LRS) at the
Hobby-Eberly- Telescope (HET) to study the kinematics of pseudobulges
and classical bulges in the nearby universe. We present major-axis
rotational velocities, velocity dispersions, and h3 and h4 moments
derived from high-resolution (39km/s) spectra for 45 S0 to Sc
galaxies; for 27 of the galaxies we also present minor axis data. We
combine our kinematics with bulge-to-disk decompositions. We
demonstrate for the first time that purely kinematic diagnostics of
the bulge dichotomy agree systematically with those based on Sersic
index. Low Sersic index bulges have both increased rotational support
(higher v/sigma values) and on average lower central velocity
dispersions. Further- more, we confirm that the same correlation also
holds when visual morphologies are used to diagnose bulge type.
The previously noted trend of photometrically flattened bulges to have
shallower velocity dispersion profiles turns to be significant and
systematic if the Sersic index is used to distinguish between
pseudobulges and classical bulges. The anti-correlation between h3 and
v/sigma observed in elliptical galaxies is also observed in
intermediate type galaxies, irrespective of bulge type. Finally, we
present evidence for formerly undetected counter rotation in the two
systems NGC 3945 and NGC 4736.
Description:
The stellar kinematics have been measured from spectra taken with the
Hobby-Eberly Telescope and the Low Resolution Spectrograph. We
observed with a slit width of 1.0-arcsec, a spectral resolution of
sigma=39km/s covering the spectral range 4790Å-5850Å, with
seeing values between 1.2 and 4-arcsec (median 2.2-arcsec). The
observed position angles correspond to the major and the minor axis.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 34 45 Galaxy sample
table8.dat 69 9122 Measured stellar kinematics
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- Galaxy Galaxy NGC number
10- 17 A8 --- HType Hubble type (RC3)
18- 21 F4.1 Mpc Dist Distance
23- 24 I2 --- r_Dist Source for distance (1)
26- 30 F5.1 mag BMAG Total absolute B magnitude (Hyperleda)
32- 33 I2 deg i Inclination angle (Hyperleda)
34 A1 --- r_i [a] a: no value in Hyperleda, from P. Erwin
(2011, private communication)
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Note (1): References as follows:
1 = Tully (1994, Cat. VII/145)
2 = Tonry et al. (2001ApJ...546..681T 2001ApJ...546..681T)
3 = de Vaucouleurs et al. (1991, Cat. VII/155)
4 = Saha et al. (2006ApJS..165..108S 2006ApJS..165..108S)
5 = Tully et al. (2009AJ....138..323T 2009AJ....138..323T)
6 = Springob et al. (2009, Cat. J/ApJS/172/599)
7 = Ekholm et al. (2000A&A...355..835E 2000A&A...355..835E)
8 = Blakeslee et al. (2009ApJ...694..556B 2009ApJ...694..556B)
9 = Riess et al. (2009, Cat. J/ApJ/699/539)
10 = Jensen et al. (2003ApJ...583..712J 2003ApJ...583..712J)
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Byte-by-byte Description of file: table8.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Galaxy Galaxy NGC number
10- 14 F5.1 deg PA Position angle
16- 20 F5.1 arcsec R Distance from the center, positive East
22- 27 F6.1 km/s RV Stellar radial velocity, positive receding
29- 31 F3.1 km/s e_RV Error on stellar radial velocity
33- 37 F5.1 km/s sigma Stellar velocity dispersion
39- 41 F3.1 km/s e_sigma Error on stellar velocity dispersion
43- 48 F6.3 km/s h3 ?=99.999 3rd order Hermite coefficient (1)
50- 55 F6.3 km/s e_h3 ?=99.999 Error on 3rd order Hermite
coefficient (1)
57- 62 F6.3 km/s h4 ?=99.999 4th order Hermite coefficient (1)
64- 69 F6.3 km/s e_h4 ?=99.999 Error on 4th order Hermite
coefficient (1)
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Note (1): the value 99.999 designates data, which are not published.
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Acknowledgements:
Maximilian Fabricius, mxhf(at)mpe.mpg.de
(End) Maximilian Fabricius [MPE, Germany], Patricia Vannier [CDS] 21-Dec-2012