J/A+A/546/A64 H and K-band stacked spectra of U/LIRGs (Piqueras Lopez+, 2012)
VLT-SINFONI integral field spectroscopy of low-z luminous and ultraluminous
infrared galaxies I. Atlas of the 2D gas structure.
Piqueras Lopez J., Colina L., Arribas S., Alonso-Herrero A., Bedregal A.G.
<Astron. Astrophys. 546, A64 (2012)>
=2012A&A...546A..64P 2012A&A...546A..64P
ADC_Keywords: Galaxies, IR ; Galaxies, spectra ; Spectra, infrared
Keywords: galaxies: general - galaxies: evolution -
galaxies: kinematics and dynamics - galaxies: ISM - Infrared: galaxies
Abstract:
We present an atlas of a sample of local (z<0.1) LIRGs (10) and ULIRGs
(7) covering the luminosity range log(LIRL☉)=11.1-12.4. The
atlas is based on near-infrared H (1.45-1.85um) and K-band
(1.95-2.45um) VLT-SINFONI integral field spectroscopy. The atlas
presents the ionised, partially ionised, and warm molecular gas 2D
flux distributions and kinematics over a FoV of ∼3x3kpc (LIRGs) and
∼12x12kpc (ULIRGs) and with average linear resolutions of ∼0.2kpc and
∼0.9kpc, respectively. The different phases of the gas show a wide
morphological variety with the nucleus as the brightest Br_g source
for ∼33% of the LIRGs and ∼71% of the ULIRGs, whereas all the LIRGs
and ULIRGs have their maximum H2 emission in their nuclear regions.
In LIRGs, the ionised gas distribution is dominated by the emission
from the star-forming rings or giant HII regions in the spiral arms.
The Brg and [FeII] line at 1.644um trace the same structures,
although the emission peaks at different locations in some of the
objects, and the [FeII] seems to be more extended and diffuse. The
ULIRG subsample is at larger distances and contains mainly
pre-coalescence interacting systems. Although the peaks of the
molecular gas emission and the continuum coincide in ∼71% of the
ULIRGs, regions with intense Paa (Brg) emission tracing luminous
star-forming regions located at distances of 2-4kpc away from the
nucleus are also detected, usually associated with secondary nuclei or
tidal tails. LIRGs have mean observed (i.e. uncorrected for internal
extinction) SFR surface densities of about 0.4 to
0.9M☉/yr/kpc2 over large areas (4-9kpc2) with peaks of about
2-2.5M☉/yr/kpc2 in the smaller regions (0.16kpc2) associated
with the nucleus of the galaxy or the brightest Brg region. ULIRGs
do have similar average SFR surface densities for the integrated
emitting regions of ∼0.4M{sun]/yr/kpc2 in somewhat larger areas
(100-200kpc2) and for the Pa_a peak (∼2M☉/yr/kpc2 in
4kpc2). The observed gas kinematics in LIRGs is primarily due to
rotational motions around the centre of the galaxy, although local
deviations associated with radial flows and/or regions of higher
velocity dispersions are present. The ionised and molecular gas share
the same kinematics (velocity field and velocity dispersion) to first
order, showing slight differences in the velocity amplitudes
(peak-to-peak) in some cases, whereas the average velocity dispersions
are compatible within uncertainties. As expected, the kinematics of
the ULIRG subsample is more complex, owing to the interacting nature
of the objects of the sample.
Description:
H- and K-band stacked spectra of the U/LIRG sample, divided into three
subsets with log(LIRL☉)<11.35 (low infra-red luminosity),
11.35≤log(LIRL☉)<12 (intermediate infra-red luminosity), and
log(LIRL☉)≥12 (high infra-red luminosity). The spectra are
normalised to a linear fit of the continuum measured within the
intervals [1.600, 1.610]um and [1.690, 1.700]um for the H-band and
[2.080, 2.115]um and [2.172, 2.204]um for the K-band. The spectra of
each galaxy in each luminosity bin are derotated, rebinned, stacked,
and convolved to a resolution of 10Å (FWHM) to achieve a
homogeneous resolution. See the text for further details.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
h_low.dat 15 2000 H-band stacked spectra for the low luminosity bin
[1.52-1.78]um
h_interm.dat 15 2000 H-band stacked spectra for the intermediate
luminosity bin [1.52-1.78]um
k_low.dat 15 2000 K-band stacked spectra for the low luminosity bin
[1.80-2.40]um
k_interm.dat 15 2000 K-band stacked spectra for the intermediate
luminosity bin [1.80-2.40]um
k_high.dat 15 2000 K-band stacked spectra for the high luminosity bin
[1.80-2.40]um
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See also:
J/AJ/121/97 : K-band spectroscopy of ULIRGs (Murphy+, 2001)
J/ApJ/658/778 : Spitzer mid-IR spectroscopy of z∼2 ULIRGs (Yan+, 2007)
J/MNRAS/395/1695 : LIRGs Spitzer mid-IR spectroscopy (Hernan-Caballero+, 2010)
Byte-by-byte Description of file: h_*.dat k_*.dat
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Bytes Format Units Label Explanations
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1- 7 F7.5 um lambda Wavelength
9- 15 F7.5 --- Flux Luminosity bin normalised flux
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Acknowledgements:
Javier Piqueras Lopez, piqueraslj(at)cab.inta-csic.es
(End) Javier Piqueras Lopez [CAB, Spain], Patricia Vannier [CDS] 30-Aug-2012