Cold Dust and its Heating Sources in M 33

Intergalactic dust and its photoelectric heating

We have examined the dust photoelectric heating in the intergalactic medium (IGM). The heating rate in a typical radiation field of the IGM is represented by Γpe = 1.2 × 10 erg s cm (D/10) (nH/10 cm) (JL/10 −21 erg s cm Hz sr) (T/10 K), where D is the dust-to-gas mass ratio, nH is the hydrogen number density, JL is the mean intensity at the hydrogen Lyman limit of the background radiation, and ...

Astronomy & Astrophysics Dust and gas power spectrum in M 33 ( HERM 33 ES )

Power spectra of deprojected images of late-type galaxies in gas or dust emission are very useful diagnostics of the dynamics and stability of their interstellar medium. Previous studies have shown that the power spectra can be approximated as two power laws, a shallow one on large scales (larger than 500 pc) and a steeper one on small scales, with the break between the two corresponding to the...

Cold dust in the starburst galaxy M 82

The starburst galaxy M82 has been mapped at λ1.2 mm using the IRAM 30–m telescope and the MPIfR 19–channel bolometer. The influence of the sidelobe pattern and the CO(2−1) line has been carefully analyzed. Based on this analysis, we conclude that the cold dust does not extend far into the halo as has been previously claimed. The total mass of dust in the inner 3 kpc of the galaxy is 7.5 · 10 M⊙...

O-33: Serum Anti-M

Quantifying the Heating Sources for Mid-infrared Dust Emissions in Galaxies: the Case of M81

With the newly available SPIRE images at 250 and 500μmfrom Herschel Space Observatory, we study quantitative correlations over a sub-kpc scale among three distinct emission components in the interstellar medium of the nearby spiral galaxy M81 (NGC3031): (a) I8 or I24, the surface brightness of the mid-infrared emission observed in the Spitzer IRAC 8 or MIPS 24μm band, with I8 and I24 being domi...