J/MNRAS/441/224 Compact FIR-bright sources in M33 (Natale+, 2014)
A multiwavelength analysis of the clumpy FIR-bright sources in M33.
Natale G., Foyle K., Wilson C.D., Kuno N.
<Mon. Not. R. Astron. Soc., 441, 224-242 (2014)>
=2014MNRAS.441..224N 2014MNRAS.441..224N
ADC_Keywords: Galaxies, nearby ; Infrared sources ; Photometry, infrared
Keywords: ISM: clouds - dust, extinction - HII regions - galaxies: ISM -
infrared: galaxies
Abstract:
We present a multiwavelength study of a sample of far-infrared (FIR)
sources detected on the Herschel broad-band maps of the nearby
galaxy M33. We perform source photometry on the FIR maps as well as
mid-infrared (MIR), Hα, far-ultraviolet and integrated Hi and CO
line emission maps. By fitting MIR/FIR dust emission spectra, the
source dust masses, temperatures and luminosities are inferred. The
sources are classified based on their Hα morphology
(sub-structured versus not-substructured) and on whether they have a
significant CO detection (S/N>3σ). We find that the sources
have dust masses in the range 102-104M☉ and that they
present significant differences in their inferred dust/star
formation/gas parameters depending on their Hα morphology and CO
detection classification. The results suggests differences in the
evolutionary states or in the number of embedded HII regions between
the sub-samples. The source background-subtracted dust emission seems
to be predominantly powered by local star formation, as indicated by a
strong correlation between the dust luminosity and the dust-corrected
Hα luminosity and the fact that the extrapolated young stellar
luminosity is high enough to account for the observed dust emission.
Finally, we do not find a strong correlation between the
dust-corrected Hα luminosity and the dust mass of the sources,
consistent with previous results on the breakdown of simple scaling
relations at sub-kpc scales. However, the scatter in the relation is
significantly reduced by correcting the Hα luminosity for the
age of the young stellar populations in the star-forming regions.
Description:
As in Foylet et al (2013MNRAS.432.2182F 2013MNRAS.432.2182F), we use FIR maps to detect
and extract the photometry of compact FIR-bright sources but also
perform the photometry at the same source locations on MIR and
Hα emission maps. In addition, we include a far-ultraviolet
(FUV) map and gas maps (CO and HI) in order to trace young stellar
populations bright in the UV and the cold gas possibly associated with
the FIR sources. Here, we describe the data reduction prior to the
source photometry.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 203 183 Source position and photometry (sections 2 and 3)
tableb1.dat 136 183 Source dust emission SED fit parameters and
source classification (sections 4 and 6)
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See also:
J/A+A/476/1161 : Spitzer photometry of M33 (Verley+, 2007)
J/ApJ/705/1364 : MIR catalog of point sources in M33 (Thompson+, 2009)
J/A+A/534/A96 : Spitzer photometry of YSC in M33 (Sharma+, 2011)
J/AJ/142/111 : Total infrared brightness and SFR in M33 (Boquien+, 2011)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ID [1/183] Source ID number
5- 13 F9.6 deg RAdeg Right Ascension J2000
15- 23 F9.6 deg DEdeg Declination J2000
25- 33 F9.4 mJy F8 Flux at 8um (IRAC)
35- 43 F9.4 mJy e_F8 Uncertainty on F8
45- 53 F9.4 mJy F24 Flux at 24um (MIPS)
55- 63 F9.4 mJy e_F24 Uncertainty on F24
65- 73 F9.4 mJy F100 Flux at 100um (PACS)
75- 83 F9.4 mJy e_F100 Uncertainty on F100
85- 93 F9.4 mJy F160 Flux at 160um (PACS)
95-103 F9.4 mJy e_F160 Uncertainty on F160
105-113 F9.4 mJy F250 ?=-999 Flux at 250um (SPIRE)
115-123 F9.4 mJy e_F250 ?=-999 Uncertainty on F250
125-133 F9.4 mJy F350 ?=-999 Flux at 350um (SPIRE)
135-143 F9.4 mJy e_F350 ?=-999 Uncertainty on F350
145-153 F9.4 10-17W/m2 FHa Hα line flux (10-14erg/cm2/s)
155-163 F9.4 10-17W/m2 e_FHa Uncertainty on FHA
165-173 F9.4 mJy FFUV ?=-999 GALEX FUV flux
175-183 F9.4 mJy e_FFUV ?=-999 Uncertainty on FFUV
185-193 F9.4 Msun/pc2 SHI HI mass surface density ΣHI
195-203 F9.4 Msun/pc2 SH2 ?=-999 H2 mass surface density ΣH2
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Byte-by-byte Description of file: tableb1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ID [1/183] Source ID number
5- 12 F8.4 --- chiUV Radiation field intensity parameter χUV
14- 21 F8.4 --- e_chiUV Uncertainty on chiUV
23- 30 F8.4 --- chiCol Radiation field colour parameter χcol
32- 39 F8.4 --- e_chiCol Uncertainty on chiCol
41- 48 F8.4 K TSED Dust temperature TSED
(for diffuse dust SED template)
50- 57 F8.4 K e_TSED Uncertainty on TSED
59- 66 F8.4 100Msun MSED Dust mass MSED
68- 75 F8.4 100Msun e_MSED Uncertainty on MSED
77- 84 F8.4 --- f24 [0/1] Fraction of 24um emission due to
emission of photo-dissociation region (PDR)
86- 93 F8.4 --- e_f24 Uncertainty on f24
95-102 F8.4 10+31W LSED Total dust luminosity LTOT (1038erg/s)
104-111 F8.4 10+31W e_LSED Uncertainty on LSED
113-120 F8.4 --- chi2fit Minimum SED fit χ2FIT
122-128 A7 --- SUB Source type from Hα: SUB or NOSUB (1)
130-136 A7 --- CO Source type CO: HighCO or LowCO (1)
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Note (1): the sources are differentiated with (see section 6):
* the Hα morphology; "NOSUB" (non-substructured) sources are
characterized by a single peak in Hα, while "SUB" (substructured)
sources show a more complex Hα morphology.
* the detection of CO: "HighCO" are weel detected, "LowCO" are not
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 02-Feb-2015