VNGS science highlight: PDR models of M51
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VNGS science highlight: PDR models of M51[C
II]/
[OI]
63
([CII]+[OI]63)/FTIR
Similar gas properties in arm and interarm regions.
Higher densities and stronger radiation fields in center
T. Parkin et al., 2013, ApJ
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M51: Gas properties from far-M51: Gas properties from far-infrared forbidden linesinfrared forbidden lines
L(TIR) [CII] 158 microns• PACS raster maps of center of M51• plus SPIRE-FTS map of [NII] 205 micron line
T. Parkin et al., 2013, ApJ
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M51: Gas properties from far-M51: Gas properties from far-infrared forbidden linesinfrared forbidden lines
[OI] 63 microns [NII] 122 microns• PACS raster maps of center of M51• Plus [OIII] 88 micron and [OI] 145 micron in strip
T. Parkin et al., 2013, ApJ
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Compare to models of Photon Compare to models of Photon Dominated Regions (PDRs)Dominated Regions (PDRs)
• Use models from Kaufman et al. 1999, ApJ– Two free parameters: strength of UV radiation field (Go) and
gas density (n)
• Some [CII] emission comes from ionized gas --> remove• [OI] high optical depth --> correct
T. Parkin et al., 2013, ApJ
Observed Corrected
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Compare to PDR modelsCompare to PDR models
Higher densities and stronger radiation fields in center
Similar gas properties in arm and interarm regions
T. Parkin et al., 2013, ApJ
NucleusCenterArmInterarm
([CII]+[OI]63)/FTIR
[CII
]/[O
I]63
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The Antennae (NGC 4038/9)The Antennae (NGC 4038/9)
Left figure: Wilson et al. 2000, ApJ;HST image: Whitmore et al. 1999, AJ
Schirm et al., 2014, ApJ
CO J=6-5 map with FTS
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Spectral Line Energy Spectral Line Energy Distributions at three positionsDistributions at three positions
[CI] lines
CO lines
Note: true intensity (not renormalized)
J(upper)Schirm et al., 2014, ApJ
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Physical properties of the Physical properties of the cold and warm gascold and warm gas
• Temperature versus density (left) and pressure (right)
• Blue = cold gas• Red = warm gas• CO+CI solutions
• Column density versus density (left) and pressure (right)
Schirm et al., 2014, ApJ
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NGC 4125: an unusual elliptical galaxyNGC 4125: an unusual elliptical galaxy
• Dust mass 6x106 Mo but only upper limits to HI and CO• submillimeter continuum follows r1/4 profile similar to stars• Dust to stellar mass ratio 3x10-5 Mo similar to other ellipticals
• Dust in this galaxy produced internally from evolved stars with gas transitioning rapidly to temperatures > 104 K
(Wilson et al., 2013, ApJL)
250 m contours on K-band image
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Priorities for future work• Continue analysis of FTS data
– M83: Wu et al. 2014 (referee report received)– M51: (Schirm et al., analysis underway)– Other galaxies: Cen A, NGC 891
• Continue analysis of PACS spectroscopy– NGC 891 (Hughes et al., first draft circulated)– Other galaxies: NGC 5195, M81, NGC 2403, M83
(outer strip only)
• Overview/cross-galaxy comparison paper(s)? Dust? Gas? Combined?
• Note: not clear who will work on remaining data …
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VNGS Publications since June, 2013
• T. Parkin et al., 2014, “The physical characteristics of the gas in the disk of Centaurus A using the Herschel Space Observatory”, ApJ, in press
• T. Hughes et al., “A resolved analysis of cold dust and gas in the nearby edge-on spiral NGC 891”, 2014, A&A
• M. Schirm et al., “Herschel-SPIRE Fourier Transform Spectrometer Observations of Excited CO and [C I] in the Antennae (NGC 4038/39): Warm and Cold Molecular Gas”, 2014, ApJ
• C. Wilson et al., “Cold Dust but Warm Gas in the Unusual Elliptical Galaxy NGC 4125”, 2013, ApJ
• T. Parkin et al., “Regional Variations in the Dense Gas Heating and Cooling in M51 from Herschel Far-infrared Spectroscopy”, 2013, ApJ
• K. Foyle et al., “Star formation and dust heating in the FIR bright sources of M83”, 2013, MNRAS
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Other plans and analysis techniques
• PACS spectroscopy cubes fully processed and ready to submit to the Herschel archive
• Foyle et al. (2013) paper on M83 applied getsources to an extragalactic source (see also Natale, Foyle et al. 2014 for M33)
• Analysis of FTS intermediate sampled maps underway using source-correction tool from Wu et al. (2013) in hipe
• Last data delivery will be FTS spectroscopy– Need to think about what products it makes sense
to deliver beyond the basic processed hipe data