J/ApJ/768/102 I-band GALFIT analysis of luminous infrared galaxies (Kim+, 2013)
Hubble space telescope ACS imaging of the GOALS sample: quantitative structural
properties of nearby luminous infrared galaxies with LIR>1011.4 L☉.
Kim D.-C., Evans A.S., Vavilkin T., Armus L., Mazzarella J.M., Sheth K.,
Surace J.A., Haan S., Howell J.H., Diaz-Santos T., Petric A., Iwasawa K.,
Privon G.C., Sanders D.B.
<Astrophys. J., 768, 102 (2013)>
=2013ApJ...768..102K 2013ApJ...768..102K (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; Galaxies, IR ; Photometry, HST ; Models
Keywords: galaxies: active - galaxies: evolution - galaxies: interactions -
galaxies: starburst - infrared: galaxies
Abstract:
A Hubble Space Telescope/Advanced Camera for Surveys study of the
structural properties of 85 luminous and ultraluminous
(LIR>1011.4 L☉) infrared galaxies (LIRGs and ULIRGs) in the
Great Observatories All-sky LIRG Survey (GOALS) sample is presented.
Two-dimensional GALFIT analysis has been performed on F814W "I-band"
images to decompose each galaxy, as appropriate, into bulge, disk,
central point-spread function (PSF) and stellar bar components. The
fraction of bulge-less disk systems is observed to be higher in LIRGs
(35%) than in ULIRGs (20%), with the disk+bulge systems making up the
dominant fraction of both LIRGs (55%) and ULIRGs (45%). Further,
bulge+disk systems are the dominant late-stage merger galaxy type and
are the dominant type for LIRGs and ULIRGs at almost every stage of
galaxy-galaxy nuclear separation. The mean I-band host absolute
magnitude of the GOALS galaxies is -22.64±0.62 mag
(1.8-0.4+1.4 L1*), and the mean bulge absolute magnitude in
GOALS galaxies is about 1.1 mag fainter than the mean host magnitude.
Almost all ULIRGs have bulge magnitudes at the high end (-20.6 to
-23.5 mag) of the GOALS bulge magnitude range. Mass ratios in the
GOALS binary systems are consistent with most of the galaxies being
the result of major mergers, and an examination of the
residual-to-host intensity ratios in GOALS binary systems suggests
that smaller companions suffer more tidal distortion than the larger
companions. We find approximately twice as many bars in GOALS
disk+bulge systems (32.8%) than in pure-disk mergers (15.9%) but most
of the disk+bulge systems that contain bars are disk-dominated with
small bulges. The bar-to-host intensity ratio, bar half-light radius,
and bar ellipticity in GOALS galaxies are similar to those found in
nearby spiral galaxies. The fraction of stellar bars decreases toward
later merger stages and smaller nuclear separations, indicating that
bars are destroyed as the merger advances. In contrast, the fraction
of nuclear PSFs increases toward later merger stages and is highest in
late-stage systems with a single nucleus. Thus, light from an active
galactic nucleus or compact nuclear star cluster is more visible at I band
as ULIRGs enter their latter stages of evolution. Finally, both GOALS
elliptical hosts and nearby Sloan Digital Sky Survey (SDSS)
ellipticals occupy the same part of the surface brightness versus
half-light radius plot (i.e., the "Kormendy Relation") and have
similar slopes, consistent with the possibility that the GOALS
galaxies belong to the same parent population as the SDSS ellipticals.
Description:
Sample galaxies were selected from a complete sample of 87 (U)LIRGs
with LIR≥1011.4 L☉ in the IRAS RBGS (i.e., f60>5.24 Jy and
Galactic Latitude |b|>5°; Sanders et al. 2003, J/AJ/126/1607).
These (U)LIRGs have been imaged with HST with the ACS/WFC using the
F435W (B) and F814W (I) broadband filters (GO program 10592,
PI: A. Evans: see A. S. Evans et al. 2013, in preparation). One galaxy
was observed per orbit in the ACCUM mode, with total exposure times of
∼21 minutes and ∼12 minutes in the F435W and F814W filters, respectively.
The F435W and F814W observations were done using the three and two point
line dither patterns, respectively. Further details of the observations
can be found in A. S. Evans et al. (2013, in preparation).
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 85 224 GALFIT Results
--------------------------------------------------------------------------------
See also:
J/AJ/126/1607 : IRAS Revised Bright Galaxy Sample (Sanders+, 2003)
J/A+A/546/A64 : H and K-band stacked spectra of U/LIRGs (Piqueras Lopez+, 2012)
J/ApJ/777/156 : Spitzer/IRS spectra of GOALS luminous IR galaxies
(Inami+, 2013)
J/ApJS/206/1 : Mid-IR properties of GOALS nearby LIRGs (Stierwalt+, 2013)
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 A19 --- Name Object name
21 A1 --- n [14B] Best fit model component in each
nucleus (1)
23- 27 F5.2 mag Imag Apparent I-band magnitude for each
component (HST ACS/WFC F814W)
29- 32 F4.1 kpc Rh Half-light radius
34- 38 F5.2 mag/arcsec mu1/2 Mean surface brightness within half-light
radius
40- 43 F4.2 --- b/a Axis ratio
45- 49 F5.2 mag ImagModel ? Apparent I-band magnitude for all model
components (HST ACS/WFC F814W)
51- 55 F5.2 mag ImagPSF ? Apparent I-band magnitude for PSF
component (HST ACS/WFC F814W)
57 A1 --- B [Y/N-] Visually-identified bar? (2)
59- 62 F4.1 % Ibar/Ihost ? Bar to host intensity ratio
64- 66 F3.1 % Ipsf/Ihost ? PSF to host intensity ratio
68- 71 F4.1 % Ires/Ihost ? Residual (total-model) to host intensity
ratio
73- 78 F6.2 mag IMagTot ? Total absolute I-band magnitude of
the system (HST ACS/WFC F814W)
80- 85 F6.2 mag IMagHost ? Host absolute I-band magnitude
(total-PSF) of the system
(HST ACS/WFC F814W)
--------------------------------------------------------------------------------
Note (1): Fit model component as follows:
1 = Sersic index n=1 (disk);
4 = Sersic index n=4 (bulge);
B = Bar component.
Note (2): If no bar is visually identified, then a "N" is placed in this column.
If GALFIT can decompose bar, then it is indicated as B in Column 2.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Prepared by Tiphaine Pouvreau [CDS] 23-Aug-2017