J/A+A/639/A61 IR continuum, [CII] and [OI] maps of M33 (Kramer+, 2020)
Gas and dust cooling along the major axis of M 33 (HerM33es).
Herschel/PACS [CII] and [OI] observations.
Kramer C., Nikola T., Anderl S., Bertoldi F., Boquien M., Braine J.,
Buchbender C., Combes F., Henkel C., Hermelo I., Israel F., Relano M.,
Roellig M., Schuster K., Tabatabaei F., van der Tak F., Verley S.,
van der Werf P., Wiedner M., Xilouris E.
<Astron. Astrophys. 639, A61 (2020)>
=2020A&A...639A..61K 2020A&A...639A..61K (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby - Interstellar medium - Spectra, infrared
Keywords: galaxies: ISM - galaxies: individual: M33 - infrared: galaxies -
infrared: ISM
Abstract:
M33 is a gas rich spiral galaxy of the Local Group. Its vicinity
allows us to study its interstellar medium (ISM) on linear scales
corresponding to the sizes of individual giant molecular clouds. We
investigate the relationship between the two major gas cooling lines
and the total infrared (TIR) dust continuum. We mapped the emission of
gas and dust in M33 using the far-infrared lines of [CII] and
[OI](63um) and the total infrared continuum. The line maps were
observed with the PACS spectrometer on board the Herschel Space
Observatory. These maps have 50pc resolution and form a ∼370pc wide
stripe along its major axis covering the sites of bright HII regions,
but also more quiescent arm and inter-arm regions from the southern
arm at 2kpc galacto-centric distance to the south out to 5.7kpc
distance to the north. Full-galaxy maps of the continuum emission at
24um from Spitzer/MIPS, and at 70um, 100um, and 160um from
Herschel/PACS were combined to obtain a map of the TIR. TIR and [CII]
intensities are correlated over more than two orders of magnitude. The
range of TIR translates to a range of far ultraviolet (FUV) emission
of G0,obs∼2 to 200 in units of the average Galactic radiation field.
The binned [CII]/TIR ratio drops with rising TIR, with large, but
decreasing scatter. The contribution of the cold neutral medium to the
[CII] emission, as estimated from VLA HI data, is on average only 10%.
Fits of modified black bodies (MBBs) to the continuum emission were
used to estimate dust mass surface densities and total gas column
densities. A correction for possible foreground absorption by cold gas
was applied to the [OI] data before comparing it with models of photon
dominated regions (PDRs). Most of the ratios of [CII]/[OI] and
([CII]+[OI])/TIR are consistent with two model solutions. The median
ratios are consistent with one solution at n∼2x102cm-3, G0∼60,
and and a second low-FUV solution at n∼104cm-3, G0∼1.5. The bulk
of the gas along the lines-of-sight is represented by a low-density,
high-FUV phase with low beam filling factors ∼1. A fraction of the gas
may, however, be represented by the second solution.
Description:
Maps of the total infrared continuum, [CII], and [OI]
intensities in erg/s/cm2/sr along the major axis of M33 (after
de-rotation by the position angle, cf. Figures 2 and 3). Data are
provided as fits files, which were created with greg/gildas.
Objects:
-----------------------------------------
RA (2000) DE Designation(s)
-----------------------------------------
01 33 50.90 +30 39 35.8 M33 = NGC 598
-----------------------------------------
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 100 3 List of fits files
fits/* . 3 Individual fits files
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See also:
J/A+A/448/1247 : XMM-Newton survey of M33 (Misanovic+, 2006)
J/A+A/472/785 : Radio continuum survey of M33 (Tabatabaei+, 2007)
J/A+A/476/1161 : Spitzer photometry of M33 (Verley+, 2007)
J/ApJS/174/366 : Chandra ACIS survey of M33 (ChaSeM33) (Plucinsky+, 2008)
J/A+A/522/A3 : M33 CO(2-1) and HI integrated intensity maps (Gratier+, 2010)
J/A+A/552/A140 : SEDs of M33 HII regions (Relano+, 2013)
J/A+A/578/A8 : Multi-resolution images of M33 (Boquien+, 2015)
J/A+A/586/A37 : M33 center and BCLMP302 [CII] spectroscopy (Mookerjea+, 2016)
Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 11 F11.7 deg RAdeg Right Ascension of center (J2000)
12- 22 F11.7 deg DEdeg Declination of center (J2000)
24- 27 I4 --- Nx Number of pixels along X-axis
29- 32 I4 --- Ny Number of pixels along Y-axis
34- 37 I4 Kibyte size Size of FITS file
39- 57 A19 --- FileName Name of FITS file, in subdirectory fits
59-100 A42 --- Title Title of the FITS file
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Acknowledgements:
Carsten Kramer, kramer(at)iram.fr
(End) Patricia Vannier [CDS] 10-May-2020