%0 Generic %1 Williams2011 %A Williams, Rik J. %A Mathur, Smita %A Poindexter, Shawn %A Elvis, Martin %A Nicastro, Fabrizio %D 2011 %K HVC distance dust %T A Spitzer-MIPS search for dust in compact high-velocity HI clouds %U http://arxiv.org/abs/1108.5181 %X We employ three-band Spitzer-MIPS observations to search for cold dust emission in three neutral hydrogen compact high-velocity clouds (CHVCs) in the vicinity of the Milky Way. Far-infrared emission correlated with HI column density was reported in HVC Complex C by Miville-Deschênes et al., indicating that this object contains dust heated by the Galactic radiation field at its distance of ~10 kpc. Our Spitzer observations are of sufficient depth to directly detect 160um dust emission in the CHVCs if it is present at the same level as in Complex C, but no emission is detected in any of the targets. For one of the targets (CHVC289) which has well-localized HI clumps, we therefore conclude that it is fundamentally different from Complex C, with either a lower dust-to-gas ratio or a greater distance from the Galactic disk (and consequently cooler dust temperature). Firm conclusions cannot be drawn for the other two Spitzer-observed CHVCs since their small-scale HI structures are not sufficiently well known; nonetheless, no extended dust emission is apparent despite their relatively high HI column densities. The lack of dust emission in CHVC289 suggests that at least some compact high-velocity clouds objects may reside far from the Galaxy.

@misc{Williams2011, abstract = { We employ three-band Spitzer-MIPS observations to search for cold dust emission in three neutral hydrogen compact high-velocity clouds (CHVCs) in the vicinity of the Milky Way. Far-infrared emission correlated with HI column density was reported in HVC Complex C by Miville-Desch\^enes et al., indicating that this object contains dust heated by the Galactic radiation field at its distance of ~10 kpc. Our Spitzer observations are of sufficient depth to directly detect 160um dust emission in the CHVCs if it is present at the same level as in Complex C, but no emission is detected in any of the targets. For one of the targets (CHVC289) which has well-localized HI clumps, we therefore conclude that it is fundamentally different from Complex C, with either a lower dust-to-gas ratio or a greater distance from the Galactic disk (and consequently cooler dust temperature). Firm conclusions cannot be drawn for the other two Spitzer-observed CHVCs since their small-scale HI structures are not sufficiently well known; nonetheless, no extended dust emission is apparent despite their relatively high HI column densities. The lack of dust emission in CHVC289 suggests that at least some compact high-velocity clouds objects may reside far from the Galaxy. }, added-at = {2011-08-29T17:14:02.000+0200}, author = {Williams, Rik J. and Mathur, Smita and Poindexter, Shawn and Elvis, Martin and Nicastro, Fabrizio}, biburl = {https://www.bibsonomy.org/bibtex/2596685e986f28e0786e36bef70055052/miki}, description = {[1108.5181] A Spitzer-MIPS search for dust in compact high-velocity HI clouds}, interhash = {f14aeafedf82f79fe59690b55e71292e}, intrahash = {596685e986f28e0786e36bef70055052}, keywords = {HVC distance dust}, note = {cite arxiv:1108.5181Comment: 8 pages, 4 figures, submitted to AJ}, timestamp = {2011-08-29T17:14:02.000+0200}, title = {A Spitzer-MIPS search for dust in compact high-velocity HI clouds}, url = {http://arxiv.org/abs/1108.5181}, year = 2011 }