J/MNRAS/456/3899 Red galaxies with pseudo-bulges in the SDSS (Ribeiro+, 2016)
Red galaxies with pseudo-bulges in the SDSS: closer to disc galaxies or
to classical bulges?
Ribeiro B., Lobo C., Anton S., Gomes J.M., Papaderos P.
<Mon. Not. R. Astron. Soc., 456, 3899-3914 (2016)>
=2016MNRAS.456.3899R 2016MNRAS.456.3899R (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, optical ; Morphology
Keywords: galaxies: bulges - galaxies: evolution - galaxies: general -
galaxies: stellar content
Abstract:
Pseudo-bulges are expected to markedly differ from classical
quasi-monolithically forming bulges in their star formation history
(SFH) and chemical abundance patterns. To test this simple
expectation, we carry out a comparative structural and spectral
synthesis analysis of 106 red massive galaxies issued from the Sloan
Digital Sky Survey (SDSS), sub-divided into bulgeless, pseudo-bulge
and classical bulge galaxies according to their photometric
characteristics, and further obeying a specific selection to minimize
uncertainties in the analysis and ensure an unbiased derivation and
comparison of SFHs. Our 2D photometry analysis suggests that discs
underlying pseudo-bulges typically have larger exponential
scalelengths than bulgeless galaxies, despite similar integral disc
luminosities. Spectral synthesis models of the stellar emission within
the 3-arcsec SDSS fibre aperture reveal a clear segregation of
bulgeless and pseudo-bulge galaxies from classical bulges on the
luminosity-weighted planes of age-metallicity and mass-metallicity,
though a large dispersion is observed within the two former classes.
The secular growth of pseudo-bulges is also reflected upon their
cumulative stellar mass as a function of time, which is shallower than
that for classical bulges. Such results suggest that the centres of
bulgeless and pseudo-bulge galaxies substantially differ from those of
bulgy galaxies with respect to their SFH and chemical enrichment
history, which likely points to different formation/assembly
mechanisms.
Description:
This study is largely motivated by and builds upon our previous work
in Coelho et al. (2013MNRAS.436.2426C 2013MNRAS.436.2426C) that focused on a sample of
massive red galaxies selected from the same NYU-VAGC catalogue of
Blanton et al. (2005AJ....129.2562B 2005AJ....129.2562B) to ascertain the frequency of
active galactic nuclei (AGN) hosted by quiescent galaxies with a
negligible or absent bulge. Since the Coelho et al.
(2013MNRAS.436.2426C 2013MNRAS.436.2426C) sample was restricted to low Sersic indices
(η<1.5), we have extended it to include as well galaxies where the
bulge has a significant contribution to the total light of the galaxy.
We thus select SDSS DR7 galaxies from the same NYU-VAGC catalogue of
Blanton et al. (2005AJ....129.2562B 2005AJ....129.2562B) that gathers photometric and
structural parameters for all SDSS galaxies having spectroscopic data.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 69 29 General properties and structural parameters for
the pseudo-bulge galaxies studied
tablea2.dat 68 38 General properties and structural parameters for
the bulgeless class galaxies studied
tablea3.dat 69 26 General properties and structural parameters for
the bulgy class galaxies studied
tablea4.dat 69 13 General properties and structural parameters for
the intermediate-eta bulge class galaxies studied
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See also:
II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)
Byte-by-byte Description of file: tablea?.dat
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Bytes Format Units Label Explanations
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1- 8 F8.4 deg RAdeg Galaxy right ascension (J2000)
10- 16 F7.4 deg DEdeg Galaxy declination (J2000)
18- 23 F6.4 --- z SDSS redshift value
25- 30 F6.4 mag g-r g-r colour index rom the NYU-VAGC catalogue
32- 37 F6.2 mag rmag Total r-band magnitude of the galaxy as
derived from GALFIT
39- 43 F5.2 kpc red ?=- Effective radius of the disk structural
component
45- 48 F4.2 kpc e_red ?=- rms uncertainty on red
50- 54 F5.2 kpc reb ?=- Effective radius of the bulge structural
component
56- 59 F4.2 kpc e_reb ?=- rms uncertainty on reb
61- 64 F4.2 --- Ser ?=- Sersic index of the bulge component
(ηb)
66- 69 F4.2 --- e_Ser ?=- rms uncertainty on Ser
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 07-Oct-2016