J/MNRAS/439/2701 Warm molecular hydrogen in ULIRGs (Hill+, 2014)
Warm molecular hydrogen in outflows from ultraluminous infrared Galaxies.
Hill M.J., Zakamska N.L.
<Mon. Not. R. Astron. Soc., 439, 2701-2716 (2014)>
=2014MNRAS.439.2701H 2014MNRAS.439.2701H
ADC_Keywords: Galaxies, IR ; Spectroscopy
Keywords: galaxies: active - galaxies: interactions - galaxies: ISM -
galaxies: starburst
Abstract:
Ultraluminous infrared galaxies (ULIRGs) show on average three times
more emission in the rotational transitions of molecular hydrogen than
expected based on their star formation rates. Using Spitzer archival
data, we investigate the origin of excess warm H2 emission in 115
ULIRGs of the IRAS 1Jy sample. We find a strong correlation between
H2 and [FeII] line luminosities, suggesting that excess H2 is
produced in shocks propagating within neutral or partially ionized
medium. This view is supported by the correlations between H2 and
optical line ratios diagnostic of such shocks. The galaxies powered by
star formation and those powered by active nuclei follow the same
relationship between H2 and [FeII], with emission line width being
the major difference between these classes (∼500 and ∼1000km/s,
respectively). We conclude that excess H2 emission is produced as
the supernovae and active nuclei drive outflows into the neutral
interstellar medium of the ULIRGs. A weak positive correlation between
H2 and the length of the tidal tails indicates that these outflows
are more likely to be encountered in more advanced mergers, but there
is no evidence for excess H2 produced as a result of the collision
shocks during the final coalescence.
Description:
We start with the Infrared Astronomical Satellite (IRAS) 1Jy sample of
118 ULIRGs (Kim & Sanders, 1998ApJS..119...41K 1998ApJS..119...41K).
Our final sample is defined by the 115 distinct Spitzer spectra (some
of which are individual components within a single IRAS source) with
both short-low (SL) observations with wavelength coverage 5.2-14.5um
and slit dimensions 4.7"x11.3" and long-low (LL) observations with
wavelength coverage 14.0-38.0um and slit dimensions 11.1"x22.3".
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 77 115 ULIRGs from IRAS 1Jy Sample that have Spitzer spectra
table2.dat 105 115 Mid-Infrared Properties: H2 and [FeII] emission
table3.dat 73 115 Mid-Infrared Properties: Si absorption and PAH
emission
table4.dat 38 115 Morphological and spectral classification
table5.dat 55 115 Optical line measurements from Veilleux et al.
(1999ApJ...522..113V 1999ApJ...522..113V, Cat. J/ApJ/522/113)
table6.dat 61 36 Optical measurements from the SDSS spectra for
a subsample of 36 ULIRGs
sp/* . 115 Individual spectra
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See also:
J/AJ/121/97 : K-band spectroscopy of ULIRGs (Murphy+, 2001)
J/A+A/409/115 : VLA imaging of IRAS 1 Jy ULIRG sample (Nagar+, 2003)
J/AJ/131/1942 : 2MASS observations of IRAS 1Jy ULIRGs (Chen+, 2006)
J/ApJ/640/167 : AGNs and ULIRGs in the CDF-South (Alonso-Herrero+, 2006)
J/MNRAS/375/115 : ULIRGs galaxies in SDSS, 2dF and 6dF (Hwang+, 2007)
J/A+A/467/565 : z=1-3 ULIRGs from the Spitzer SWIRE survey (Berta+, 2007)
J/ApJ/658/778 : Spitzer mid-IR spectroscopy of z∼2 ULIRGs (Yan+, 2007)
J/ApJ/674/172 : Oxygen abundances of LIRGs and ULIRGs (Rupke+, 2008)
J/MNRAS/405/2505 : Nuclear activity in ULIRGs (Nardini+, 2010)
J/MNRAS/414/702 : Optical classification of southern ULIRGs (Lee+, 2011)
J/ApJS/203/3 : Spectroscopy of 39 IRAS 1Jy sample ULIRG (Soto+, 2012)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- --- [IRAS]
6- 15 A10 --- IRAS IRAS designation (HHMMm+DDMM, B1950) (from NED)
16 A1 --- --- [:]
17- 18 A2 --- m_IRAS IRAS component designation (G1)
21- 25 F5.3 --- z Redshift
28- 37 F10.6 deg RAdeg Right Ascension (J2000.00) (from Spitzer RA_RQST)
40- 49 F10.6 deg DEdeg Declination (J2000.00) (from Spitzer DEC_RQST)
52- 56 F5.3 --- MF [0/1] Multiplicative Factor applied to the LL
(Long-Low) orders to bring LL flux density in
agreement with SL flux density orders at 14um
58-77 A20 --- FileName Name of the file with spectrum in subdirectory sp
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [IRAS]
6- 15 A10 --- IRAS IRAS designation (HHMMm+DDMM, B1950) (from NED)
16 A1 --- --- [:]
17- 18 A2 --- m_IRAS IRAS component designation (G1)
21- 29 E9.4 10-7W LS(1) Luminosity of the S(1) H2 emission line
31- 39 E9.4 10-7W e_LS(1) rms uncertainty on LS(1) transition
41- 49 E9.4 10-7W LS(3) Luminosity of the S(3) H2 emission line
51- 59 E9.4 10-7W e_LS(3) rms uncertainty on LS(3) transition
61- 64 I4 K Texc Excitation Temperature derived from
S(3)-S(1) transition
67- 69 I3 K e_Texc rms uncertainty on Texc
71- 79 E9.4 10-7W L[FeII] Luminosity of the [FeII]5.34um emission line
81- 89 E9.4 10-7W e_L[FeII] rms uncertainty on L[FeII]
91- 95 F5.3 um EWPAH Equivalent Width of PAH[6.2um]
97-105 E9.4 um e_EWPAH rms uncertainty on EWPAH
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- --- [IRAS]
6- 15 A10 --- IRAS IRAS designation (HHMMm+DDMM, B1950)
16 A1 --- --- [:]
17- 18 A2 --- m_IRAS IRAS component designation (G1)
21- 24 F4.2 --- tau(9.7) Strength of the silicate feature at 9.7um
26- 30 F5.2 10+35W L(6.2) Luminosity of PAH[6.2um] emission feature
32- 36 F5.2 10+35W e_L(6.2) rms uncertainty on L(6.2)
38- 43 F6.2 10+35W L(7.7) Luminosity of PAH[7.7um] emission feature
45- 49 F5.2 10+35W e_L(7.7) rms uncertainty on L(7.7)
51- 55 F5.2 10+35W L(8.5) Luminosity of PAH[8.5um] emission feature
57- 61 F5.2 10+35W e_L(8.5) rms uncertainty on L(8.5)
63- 67 F5.2 10+35W L(11.3) Luminosity of PAH[11.3um] emission feature
69- 73 F5.2 10+35W e_L(11.3) rms uncertainty on L(11.3)
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [IRAS]
6- 15 A10 --- IRAS IRAS designation (HHMMm+DDMM, B1950) (from NED)
16 A1 --- --- [:]
17- 18 A2 --- m_IRAS IRAS component (G1)
21- 24 F4.1 kpc NS Projected Nuclear Separation (1)
26- 29 F4.1 kpc TL Length of Tidal Tails (1)
32- 34 A3 --- MS Merger Stage (1)
37- 38 A2 --- SpT Spectral Type (2)
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Note (1): from Veilleux et al. 2002 (J/ApJS/143/315). Merger stages are:
III pre-merger galaxies
IV = merger galaxies
V = old mergers
Note (2): from Yuan et al. 2010 (J/ApJ/709/884):
S1 = broad-line active nuclei
S2 = narrow-line active nuclei
H = purely star-forming galaxies
cp = composite galaxies
L = liners
NA = classification is not available
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [IRAS]
6- 15 A10 --- IRAS IRAS designation (HHMMm+DDMM, B1950)
16 A1 --- --- [:]
17- 18 A2 --- m_IRAS IRAS component (G1)
21- 24 F4.2 [-] Ha/Hb ?=- Logarithm of flux of Hα relative
to Hβ
26- 31 F6.1 km/s W[OIII] ?=- Full width at half-maximum (FWHM) i
of [OIII]5007Å
33- 37 F5.2 [-] OIII/Hb ?=- Logarithm of flux of [OIII]5007Å
relative to Hβ
39- 43 F5.2 [-] NII/Ha ?=- Logarithm of flux of [NII]6583Å
relative to Hα
45- 49 F5.2 [-] SII/Ha ?=- Logarithm of flux of the sum of
[SII]6716,6721Å relative to Hα
51- 55 F5.2 [-] OI/Ha ?=- Logarithm of flux of [OI]6300Å
relative to Hα
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [IRAS]
6- 15 A10 --- IRAS IRAS designation (HHMMm+DDMM, B1950)
16 A1 --- --- [:]
17- 18 A2 --- m_IRAS IRAS component (G1)
21- 22 I2 --- Index 0-based index of the object in Tables 1-5
24- 38 A15 --- PMF SDSS spectroscopic identification
(plate-MJD-fiber)
40- 43 I4 km/s vNa Velocity centroid of the Na D absorption
feature relative to the stellar continuum
45- 49 F5.2 0.1nm EWNaD Estimated equivalent width of Na D absorption
51- 55 I5 km/s v02 Maximal blueshift of the [OIII]5007 emission
line v02
58- 61 I4 km/s w90 Velocity width containing 90% of [OIII]5007
emission line power
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Byte-by-byte Description of file(#): sp/*
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Bytes Format Units Label Explanations
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1 I1 --- Order Order
3- 10 F8.5 um lambda [5.2/38] Wavelength λ
12- 20 F9.6 Jy S Flux density
22- 30 F9.6 Jy e_S rms uncertainty on S
33- 37 I5 --- Flag [0/16383] Bit-flag
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Global notes:
Note (G1): using images from Kim et al. 2002 (J/ApJS/143/277).
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 19-Dec-2014