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. =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 H_2_ emission in 115 ULIRGs of the IRAS 1Jy sample. We find a strong correlation between H_2_ and [FeII] line luminosities, suggesting that excess H_2_ is produced in shocks propagating within neutral or partially ionized medium. This view is supported by the correlations between H_2_ 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 H_2_ and [FeII], with emission line width being the major difference between these classes (~500 and ~1000km/s, respectively). We conclude that excess H_2_ emission is produced as the supernovae and active nuclei drive outflows into the neutral interstellar medium of the ULIRGs. A weak positive correlation between H_2_ 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 H_2_ 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). 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: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table1.dat 77 115 ULIRGs from IRAS 1Jy Sample that have Spitzer spectra table2.dat 105 115 Mid-Infrared Properties: H_2_ 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, 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 -------------------------------------------------------------------------------- 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 -------------------------------------------------------------------------------- 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- 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 -------------------------------------------------------------------------------- Byte-by-byte Description of file: table2.dat -------------------------------------------------------------------------------- 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) H_2_ 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) H_2_ 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 -------------------------------------------------------------------------------- Byte-by-byte Description of file: table3.dat -------------------------------------------------------------------------------- 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 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) -------------------------------------------------------------------------------- Byte-by-byte Description of file: table4.dat -------------------------------------------------------------------------------- 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) -------------------------------------------------------------------------------- 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 -------------------------------------------------------------------------------- Byte-by-byte Description of file: table5.dat -------------------------------------------------------------------------------- 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 H{alpha} relative to H{beta} 26- 31 F6.1 km/s W[OIII] ?=- Full width at half-maximum (FWHM) i of [OIII]5007{AA} 33- 37 F5.2 [-] OIII/Hb ?=- Logarithm of flux of [OIII]5007{AA} relative to H{beta} 39- 43 F5.2 [-] NII/Ha ?=- Logarithm of flux of [NII]6583{AA} relative to H{alpha} 45- 49 F5.2 [-] SII/Ha ?=- Logarithm of flux of the sum of [SII]6716,6721{AA} relative to H{alpha} 51- 55 F5.2 [-] OI/Ha ?=- Logarithm of flux of [OI]6300{AA} relative to H{alpha} -------------------------------------------------------------------------------- Byte-by-byte Description of file: table6.dat -------------------------------------------------------------------------------- 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 -------------------------------------------------------------------------------- Byte-by-byte Description of file(#): sp/* -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1 I1 --- Order Order 3- 10 F8.5 um lambda [5.2/38] Wavelength {lambda} 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 -------------------------------------------------------------------------------- Global notes: Note (G1): using images from Kim et al. 2002 (J/ApJS/143/277). -------------------------------------------------------------------------------- History: From electronic version of the journal ================================================================================ (End) Patricia Vannier [CDS] 19-Dec-2014