J/ApJ/757/13 IR SEDs of 24um z∼0.3-3 galaxies (Sajina+, 2012)
Spitzer- and Herschel-based spectral energy distributions of 24 µm bright
z ∼ 0.3-3.0 starbursts and obscured quasars.
Sajina A., Yan L., Fadda D., Dasyra K., Huynh M.
<Astrophys. J., 757, 13 (2012)>
=2012ApJ...757...13S 2012ApJ...757...13S
ADC_Keywords: Spectra, infrared ; Galaxies, IR ; Active gal. nuclei ;
Energy distributions ; Redshifts
Keywords: galaxies: active; galaxies: evolution; galaxies: high-redshift;
galaxies: starburst; infrared: galaxies
Abstract:
In this paper, we characterize the infrared spectral energy
distributions (SEDs) of mid-IR-selected z∼0.3-3.0 and
LIR∼1011-1013L☉ galaxies, and study how their SEDs differ
from those of local and high-z analogs. Infrared SEDs depend both on
the power source (AGN or star formation) and the dust distribution.
Therefore, differences in the SEDs of high-z and local galaxies
provide clues as to differences in their physical conditions. Our
mid-IR flux-limited sample of 191 sources is unique in size, and
spectral coverage, including Spitzer mid-IR spectroscopy. Here, we add
Herschel photometry at 250µm, 350µm, and 500µm, which allows
us, through fitting an empirical SED model, to obtain accurate total
IR luminosities, as well as constrain the relative contributions of
AGNs and starbursts to those luminosities. Our sample includes three
broad categories of SEDs: ∼23% of the sources are AGNs (i.e., where
the AGN contributes >50% of LIR), ∼30% are starbursts where an AGN
contributes <20% of LIR, and the mid-IR spectra are starburst-like
(i.e., strong polycyclic aromatic hydrocarbon features); and the
largest group (∼47%) are composites which show both significant AGN
and starburst activity. In summary, our results show that there is
strong evolution in the SEDs between local and z∼2 IR-luminous
galaxies, as well as that there is a wide range of SEDs among high
redshift IR-luminous sources. The publicly available SED templates we
derive from our sample will be particularly useful for infrared
population synthesis models, as well as in the interpretation of other
mid-IR high-z galaxies, in particular those detected by the recent all
sky Wide-field Infrared Survey Explorer.
Description:
A number of programs, the largest of which is by our own group,
involve Spitzer Infrared Spectrograph (IRS) spectra of 24um bright
sources in the Spitzer Extragalactic First Look Survey (xFLS) field.
We combine our IRS data with archival data to construct an xFLS "IRS
supersample" of 191 sources. The criteria for this supersample are:
(1) to be located in the inner 2.7deg2 of the xFLS, (2) to have a
24um flux of F24>0.9mJy, and (3) to have an R magnitude of R≥20. The
bulk of the IRS sample comes from our Spitzer GO2 program (see Dasyra
et al. 2009, Cat. J/ApJ/701/1123, for details), followed by our
Spitzer GO1 sources (Yan et al. 2007, Cat. J/ApJ/658/778; Sajina et
al. 2007ApJ...664..713S 2007ApJ...664..713S). An additional 17 sources from several
different programs (Weedman et al. 2006ApJ...638..613W 2006ApJ...638..613W; Lacy et al.
2007ApJ...669L..61L 2007ApJ...669L..61L; Martinez-Sansigre et al. 2008ApJ...674..676M 2008ApJ...674..676M)
also meet our selection criteria. Combined, these samples constitute a
"supersample" of 212, of which, 191 have redshifts (see Section 2.2).
In this paper, we only consider the sources with redshifts.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 53 191 Source names, redshift, mid-IR fitting results
and references
table2.dat 153 191 Broadband photometry
table3.dat 114 191 SED-fitting-derived quantities
--------------------------------------------------------------------------------
See also:
VI/139 : Herschel Observation Log (Herschel Science Centre, 2013)
VIII/95 : Herschel Multi-tiered Extragalactic Survey (Oliver+, 2012)
J/AJ/144/11 : IR imaging, SEDs, Spitzer spectra of 22 AGNs (Mason+, 2012)
J/AJ/143/125 : SED of 113 dust-obscured galaxies at z∼2 (Melbourne+, 2012)
J/ApJS/193/13 : Spitzer/IRAC sources in the EGS I. SEDs (Barro+, 2011)
J/ApJ/730/125 : HST/NICMOS obs. of bright IR galaxies (Zamojski+, 2011)
J/ApJ/723/1110 : MIPS 24um observations of the HDFS (Huynh+, 2010)
J/MNRAS/409/2 : Herschel sources SED model parameters (Rowan-Robinson+, 2010)
J/MNRAS/395/1695 : Spitzer MIR spectroscopy of LIRGs (Hernan-Caballero+, 2009)
J/ApJS/182/628 : Spitzer quasar and ULIRG evolution study (Veilleux+, 2009)
J/AJ/138/1261 : Spitzer/MIPS observations of the COSMOS field (Frayer+, 2009)
J/ApJ/706/1364 : SINS survey of high-redshift gal. (Forster Schreiber+, 2009)
J/ApJ/701/1123 : MIR spectroscopic catalog of 150 galaxies (Dasyra+, 2009)
J/ApJ/692/556 : Star forming galaxy templates (Rieke+, 2009)
J/ApJ/666/806 : SED of Spitzer quasars (QUEST) (Netzer+, 2007)
J/ApJ/663/218 : Optical Spectro. of WIYN Hydra FLS sources (Marleau+, 2007)
J/ApJ/658/778 : Spitzer mid-IR spectroscopy of z∼2 ULIRGs (Yan+, 2007)
J/AJ/133/186 : Optical spectro. of 77 luminous AGNs and QSOs (Lacy+, 2007)
J/MNRAS/376/1251 : 610MHz observations of Spitzer XFLS (Garn+, 2007)
J/AJ/132/231 : MMT hectospec z survey of 24um sources (Papovich+, 2006)
J/AJ/131/2859 : Extragalactic First Look Survey: 24µm data (Fadda+, 2006)
J/AJ/131/250 : Spitzer 70 and 160um observations in xFLS (Frayer+, 2006)
J/ApJS/166/470 : SDSS-Spitzer type I QSOs IR photometry (Richards+, 2006)
J/A+A/424/371 : 1.4GHz First Look Survey (FLS) (Morganti+, 2004)
J/AJ/128/1 : First Look Survey: NOAO R-band Mosaic (Fadda+, 2004)
J/AJ/125/2411 : SIRTF First-Look Survey (Condon+, 2003)
J/ApJS/143/315 : IRAS 1Jy sample of ultraluminous gal. II. (Veilleux+, 2002)
http://ssc.spitzer.caltech.edu/fls/ : Spitzer First Look Survey home page
http://heasarc.gsfc.nasa.gov/W3Browse/all/spitzmastr.html : SST log homepage
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- Name Source name (G1)
11- 15 F5.3 --- z [0.24/3.49] Redshift (1)
16 A1 --- u_z [?] Discrepant redshift (2)
18 A1 --- l_W(7.7) Limit flag on EW7.7
19- 22 F4.2 um W(7.7) [0.15/9.84] Equivalent width of the 7.7um PAH
feature
24- 27 F4.2 um e_W(7.7) [0.05/0.7]? Uncertainty on the equivalent width
of the 7.7um PAH feature
29- 31 F3.1 --- tau9.7 [0/8.3] The optical depth of the 9.7um silicate
feature
33- 39 A7 --- OT Object classification: AGN, QSO, SB=starburst
galaxy, or galaxy
41- 48 A8 --- Ref References (3)
50- 53 F4.2 --- zIRS ? Spitzer/IRS redshift when available
--------------------------------------------------------------------------------
Note (1): We adopt the optical/near-IR spectroscopic redshifts whenever
available (see references), otherwise we adopt the mid-IR IRS
redshifts from Dasyra et al. (2009, Cat. J/ApJ/701/1123;
<[DYH2009] MIPS NNNNN> in Simbad), and some from Sajina et al.
(2007ApJ...664..713S 2007ApJ...664..713S).
Note (2): Redshifts where the optical and IRS redshifts are discrepant are
marked with "?". We also mark with "?" the IRS redshifts that are
based on very weak and uncertain features.
Note (3): The references for the optical/near-IR spectroscopic redshifts and
classification whenever available as follows:
L07 = Lacy et al. 2007ApJ...669L..61L 2007ApJ...669L..61L; see also 2007, Cat. J/AJ/133/186
L11 = Lacy et al. 2011AJ....142..196L 2011AJ....142..196L
P06 = Papovich et al. 2006, Cat. J/AJ/132/231; <[PCE2006] NNNN> in Simbad
C06 = Choi et al. 2006ApJ...637..227C 2006ApJ...637..227C
D09 = Dasyra et al. 2009, Cat. J/ApJ/701/1123
S08 = Sajina et al. 2008ApJ...683..659S 2008ApJ...683..659S
MS06 = Martinez-Sansigre et al. 2006MNRAS.370.1479M 2006MNRAS.370.1479M
H09 = Hernan-Caballero et al. 2009, Cat. J/MNRAS/395/1695
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- Name Source name (G1)
11 A1 --- l_F0.64 Limit flag on F0.64 (4)
13- 18 F6.3 uJy F0.64 [0.19/30.5] R-band flux density (0.64um)
20 A1 --- l_F3.6 Limit flag on F3.6 (4)
22- 24 I3 uJy F3.6 [6/584] Spitzer/IRAC 3.6um flux density
26- 27 I2 uJy e_F3.6 [1/59]? uncertainty on the 3.6um flux density
29 A1 --- l_F4.5 Limit flag on F4.5 (4)
31- 33 I3 uJy F4.5 [10/819] Spitzer/IRAC 4.5um flux density
35- 36 I2 uJy e_F4.5 [2/83]? uncertainty on the 4.5um flux density
38 A1 --- l_F5.8 Limit flag on F5.8 (4)
40- 43 I4 uJy F5.8 [27/1588]? Spitzer/IRAC 5.8um flux density
45- 47 I3 uJy e_F5.8 [7/161]? uncertainty on the 5.8um flux density
49 A1 --- l_F8.0 Limit flag on F8.0 (4)
51- 54 I4 uJy F8.0 [36/3705] Spitzer/IRAC 8.0um flux density
56- 58 I3 uJy e_F8.0 [8/372]? uncertainty on the 8.0um flux density
60- 63 F4.2 mJy F24 [0.84/9.41] Spitzer/MIPS 24um flux density
65- 68 F4.2 mJy e_F24 [0.03/0.07] F24 uncertainty
70 A1 --- l_F70 Limit flag on F70 (4)
72- 76 F5.1 mJy F70 [0/222] Spitzer/MIPS 70um flux density
78- 81 F4.1 mJy e_F70 [0/30]? uncertainty on the 70um flux density
83 A1 --- l_F160 Limit flag on F160 (4)
85- 89 F5.1 mJy F160 [13/329] Spitzer/MIPS 160um flux density
91- 94 F4.1 mJy e_F160 [8.8/46]? uncertainty on the 160um flux density
96 A1 --- l_F250 Limit flag on F250 (4)
98- 99 I2 mJy F250 [12/74] SPIRE 250um flux density
101 I1 mJy e_F250 [1/9]? uncertainty on the 250um flux density
103 A1 --- l_F350 Limit flag on F350 (4)
105-106 I2 mJy F350 [12/56] SPIRE 350um flux density
108 I1 mJy e_F350 [1/8]? uncertainty on the 350um flux density
110 A1 --- l_F500 Limit flag on F500 (4)
112-113 I2 mJy F500 [12/78] SPIRE 500um flux density
115 I1 mJy e_F500 [5/9]? uncertainty on the 500um flux density
117-122 F6.3 mJy F1200 [-1/3.5]? MAMBO 1.2mm flux density
124-127 F4.2 mJy e_F1200 [0.3/1.1]? uncertainty on the 1.2mm flux density
129-135 F7.4 mJy F20cm [0.04/18]? 1.4GHz (20cm) flux density
137-142 F6.4 mJy e_F20cm [0.007/1.3]? F20cm uncertainty
144-148 F5.2 mJy F49cm [0.18/26]? GMRT 610MHz flux density
150-153 F4.2 mJy e_F49cm [0.05/0.4]? F610MHz uncertainty
--------------------------------------------------------------------------------
Note (4): Upper limits are 3σ
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- Name Source name (G1)
11- 13 F3.1 --- ahot spectral index α of hot component (G2)
15- 18 F4.1 K T [11/98] cold component dust temperature (G2)
19 A1 --- f_T [*] T is fixed (5)
21- 23 F3.1 --- beta cold component β index (G2)
24 A1 --- f_beta [*] β is fixed (5)
26- 32 F7.3 Lsun L1.6s ? 1.6um νLν luminosity where only the
stellar component is included
34- 39 F6.3 Lsun L5.8 5.8um luminosity
41- 46 F6.3 Lsun L15 15um luminosity
48- 52 F5.2 Lsun L30 30um luminosity
54 A1 --- l_L20cm Limit flag on L20cm
55- 59 F5.2 W/Hz L20cm 1.4GHz (20cm) luminosity
61- 64 F4.2 W/Hz e_L20cm ? uncertainty on the 1.4GHz luminosity
66- 71 F6.3 Lsun LAGN AGN luminosity (based on the integrated
3-1000um hot component emission)
73- 77 F5.2 Lsun LIR IR luminosity (3-1000um)
79- 84 F6.2 Lsun e_LIR Uncertainty on the IR luminosity
86- 92 F7.2 Msun/yr SFR ? Star-formation rate (6)
94- 95 I2 % fAGN [0/99] The maximum likelihood of LAGN/LIR
97- 98 I2 % e_fAGN [1/85] fAGN uncertainty
100-114 A15 --- Class SED type classification: Starburst, Composite,
Starburst-A (strong far-IR), high-tau9.7 AGN
or low-tau9.7 AGN.
--------------------------------------------------------------------------------
Note (5): The cold component parameters Tdust and beta are marked with * if
they are held fixed at these values rather than being the best-fit values.
Note (6): Based on the conversion from LIR in Kennicutt 1998ARA&A..36..189K 1998ARA&A..36..189K
--------------------------------------------------------------------------------
Global note:
Note (G1): Sources are <[DYH2009] MIPS NNNNN> or
<[YSF2007] MIPS NNNNN> in Simbad or
Spitzer AORKey for NNNNNNNN formats.
Note (G2): The model is made of 5 components ("F" represents νFν):
F = a*F* + aPAHFPAH + ahotFhot + awarmFwarm + acoldFcold
F* = 1.6µm stellar bump, assuming a 2Gyr old simple stellar population
FPAH = fixed template based on the NGC 7714 starburst described by
Sajina et al. 2007ApJ...664..713S 2007ApJ...664..713S
Fhot = ν[(ν/ν0)αe0.5ν + (ν/ν0)-0.5
+ (ν/0.3ν0)-3]-1
Fwarm = ν1-αwexp(-ν0/ν) (very small grains)
Fcold = aν(1-exp(-(ν/ν0)β)B(ν,T)
History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 19-May-2014