J/ApJ/819/69 [NII]205um emission in local luminous IR galaxies (Zhao+, 2016)
The [NII] 205 µm emission in local luminous infrared galaxies.
Zhao Y., Lu N., Xu C.K., Gao Y., Lord S.D., Charmandaris V.,
Diaz-Santos T., Evans A., Howell J., Petric A.O., van der Werf P.P.,
Sanders D.B.
<Astrophys. J., 819, 69 (2016)>
=2016ApJ...819...69Z 2016ApJ...819...69Z (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; Galaxies, IR ; Spectra, infrared
Keywords: galaxies: evolution; galaxies: ISM; infrared: ISM;
galaxies: luminosity function, mass function; galaxies: starburst
Abstract:
In this paper, we present the measurements of the [NII]205µm line
for a flux-limited sample of 122 (ultra-)luminous infrared galaxies
[(U)LIRGs] and 20 additional normal galaxies, obtained with the
Herschel Space Observatory (Herschel). We explore the far-infrared
(FIR) color dependence of the [NII]205µm (L[NII]205µm) to the
total infrared (LIR) luminosity ratio, and find that
L[NII]205µm/LIR only depends modestly on the 70-160µm flux
density ratio (f70/f160) when f70/f160≲0.6, whereas such dependence
becomes much steeper for f70/f160>0.6. We also investigate the
relation between L[NII]205µm and star formation rate (SFR), and
show that L[NII]205µm has a nearly linear correlation with SFR,
albeit the intercept of such a relation varies somewhat with f60/f100,
consistent with our previous conclusion that [NII]205µm emission
can serve as an SFR indicator with an accuracy of ∼0.4dex, or ∼0.2dex
if f60/f100 is known independently. Furthermore, together with the
Infrared Space Observatory measurements of [NII], we use a total of
∼200 galaxies to derive the local [NII]205µm luminosity function
(LF) by tying it to the known IR LF with a bivariate method. As a
practical application, we also compute the local SFR volume density
(ρSFR) using the newly derived SFR calibrator and LF. The
resulting logρSFR=-1.96±0.11M☉/yr/Mpc3 agrees well
with previous studies. Finally, we determine the electron densities
(ne) of the ionized medium for a subsample of 12 (U)LIRGs with both
[NII]205µm and [NII]122µm data, and find that ne is in the
range of ∼1-100/cm3, with a median value of 22/cm3.
Description:
The primary sample studied in this paper is from the Herschel open
time project Herschel Spectroscopic Survey of Warm Molecular Gas in
Local Luminous Infrared Galaxies (OT1nlu1; PI: N. Lu).
The observations were conducted with the Herschel SPIRE/FTS in its
point source spectroscopy mode and high spectral resolution
configuration, yielding a spectral resolution of 0.04/cm (or 1.2GHz)
over the spectral coverage of 194-672um.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 107 196 Fluxes of the [NII] 205 micron emission
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See also:
VI/139 : Herschel Observation Log (Herschel Science Centre, 2013)
VI/111 : ISO Observation Log (ISO Data Centre, 2004)
J/A+A/578/A53 : Spectroscopy of Herschel Dwarf Galaxy Survey (Cormier+, 2015)
J/A+A/575/A17 : NGC 891 Herschel PACS and SPIRE spectroscopy (Hughes+, 2015)
J/ApJ/774/68 : [CII]157.7um feature in LIRGs (Diaz-Santos+, 2013)
J/ApJS/206/1 : Mid-IR properties of GOALS nearby LIRGs (Stierwalt+, 2013)
J/ApJ/777/156 : Spitzer/IRS spectra of GOALS luminous IR gal. (Inami+, 2013)
J/ApJ/739/100 : [NII] observations of NGC 3372 (Oberst+, 2011)
J/A+A/529/A149 : HII regions in low-metallicity galaxies (Guseva+, 2011)
J/ApJ/715/572 : GOALS UV and FIR properties (Howell+, 2010)
J/ApJS/182/628 : Spitzer quasar and ULIRG evolution study (Veilleux+, 2009)
J/ApJS/178/280 : Compendium of ISO far-IR extragalactic data (Brauher+, 2008)
J/ApJS/173/185 : GALEX ultraviolet atlas of nearby galaxies (Gil de Paz+, 2007)
J/A+A/430/725 : N II effective collision strengths (Hudson+, 2005)
J/AJ/126/1607 : IRAS Revised Bright Galaxy Sample (Sanders+, 2003)
J/ApJ/554/803 : New VLA Sky Survey (NVSS) Cat of IRAS 2Jy Galaxies (Yun+ 2001)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- Sample Sample (1)
16- 30 A15 --- Name Galaxy identifier
32- 33 I2 h RAh Hour of Right Ascension (J2000) (2)
35- 36 I2 min RAm Minute of Right Ascension (J2000) (2)
38- 41 F4.1 s RAs Second of Right Ascension (J2000) (2)
43 A1 --- DE- Sign of the Declination (J2000) (2)
44- 45 I2 deg DEd Degree of Declination (J2000) (2)
47- 48 I2 arcmin DEm Arcminute of Declination (J2000) (2)
50- 53 F4.1 arcsec DEs Arcsecond of Declination (J2000) (2)
55- 64 I10 --- ObsId Herschel or ISO observation identifier
66 A1 --- l_FNII 3σ upper limit flag on FNII
67- 72 F6.2 10-17W/m2 FNII [0.5/504] The [NII]205um flux (3)
74- 78 F5.2 10-17W/m2 e_FNII [0.1/34.1]?=0 Uncertainty in FNII
80- 85 F6.2 --- Corr [1/4.6]?=-99 Correction factor (4)
87- 91 F5.1 Msun/yr SFR [-2.3/500]?=-99 Star Formation Rate
(see Section 3.1)
93- 99 F7.2 Jy F60 [0.7/1481] IRAS 60 micron band flux density
101-107 F7.2 Jy F100 [0.3/1373] IRAS 100 micron band flux density
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Note (1): Sample as follows:
GOALS-FTS = The 122 galaxies (111 LIRGs and 11 ULIRGs) observed with Herschel
SPIRE/FTS for the [NII]205um data.
ISO = 53 unresolved galaxies (23 detections and 30 upper limits) observed
by the Infrared Space Observatory (ISO) Long Wavelength
Spectrometer (LWS), for which the [NII]122um fluxes were measured
by Brauher et al. (2008, J/ApJS/178/280).
Mapping-Galaxy = To increase the sample size and dynamic range of our study, we
also include in our analysis 20 nearby normal galaxies having
Herschel SPIRE/FTS mapping observations that cover the entire
galaxy.
See section 2 for further explanations.
Note (2): For the GOALS-FTS sample, the coordinate gives the position where
the Herschel SPIRE/FTS observation was pointed.
Note (3): Measured from the SPIRE/FTS spectra for the GOALS-FTS and Mapping
Galaxy samples; obtained from [NII]122 micron emission for
the ISO sample.
Note (4): For the GOALS-FTS sample, correction factor (fcorr) applied to
FNII to obtain the total [NII] 205 micron flux (see Section 2.1.1
for details). For the ISO sample, the [NII]122 micron - to-
[NII]205 micron conversion factor (R122/205).
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 23-May-2016