Planck Early Results XXIV: Dust in the diffuse interstellar medium and the Galactic halo
Abstract
This paper presents the first results of comparison of Planck along with IRAS data with Green Bank Telescope 21-cm observations in 14 fields covering more than 800 square degrees at high Galactic latitude. Galactic dust emission for fields with average HI column density lower than 2 x 10^20 cm^-2 is well correlated with 21-cm emission. The residual emission in these fields, once the HI-correlated emission is removed, is consistent with the expected statistical properties of the cosmic infrared background fluctuations. Fields with larger column densities show significant excess dust emission compared to the HI column density. Regions of excess lie in organized structures that suggest the presence of hydrogen in molecular form, though they are not always correlated with CO emission. Dust emission from intermediate-velocity clouds is detected with high significance. Its spectral properties are consistent with, compared to the local ISM values, significantly hotter dust (T~20 K), lower sub-millimeter dust opacity, and a relative abundance of very small grains to large grains about four times higher. These results are compatible with expectations for clouds that are part of the Galactic fountain in which there is dust shattering and fragmentation. Correlated dust emission in HVCs is not detected; the average of the 99.9% confidence upper limits to the emissivity is 0.15 times the local ISM value at 857 and 3000 GHz, in accordance with gas phase evidence for lower metallicity and depletion in these clouds. Unexpected anti-correlated variations of the dust temperature and emission cross-section per H atom are identified in the local ISM and IVCs, a trend that continues into molecular environments. This suggests that dust growth through aggregation, seen in molecular clouds, is active much earlier in the cloud condensation and star formation processes.
Keywords
Cite
@article{arxiv.1101.2036,
title = {Planck Early Results XXIV: Dust in the diffuse interstellar medium and the Galactic halo},
author = {Planck Collaboration and A. Abergel and P. A. R. Ade and N. Aghanim and M. Arnaud and M. Ashdown and J. Aumont and C. Baccigalupi and A. Balbi and A. J. Banday and R. B. Barreiro and J. G. Bartlett and E. Battaner and K. Benabed and A. Benoit and J. -P. Bernard and M. Bersanelli and R. Bhatia and K. Blagrave and J. J. Bock and A. Bonaldi and J. R. Bond and J. Borrill and F. R. Bouchet and F. Boulanger and M. Bucher and C. Burigana and P. Cabella and C. M. Cantalupo and J. -F. Cardoso and A. Catalano and L. Cayon and A. Challinor and A. Chamballu and L. -Y Chiang and C. Chiang and P. R. Christensen and D. L. Clements and S. Colombi and F. Couchot and A. Coulais and B. P. Crill and F. Cuttaia and L. Danese and R. D. Davies and R. J. Davis and P. de Bernardis and G. de Gasperis and A. de Rosa and G. de Zotti and J. Delabrouille and J. -M. Delouis and F. -X. Desert and C. Dickinson and S. Donzelli and O. Dore and U. Dorl and M. Douspis and X. Dupac and G. Efstathiou and T. A. Ensslin and H. K. Eriksen and F. Finelli and O. Forni and M. Frailis and E. Franceschi and S. Galeotta and K. Ganga and M. Giard and G. Giardino and Y. Giraud-Heraud and J. Gonzalez-Nuevo and K. M. Gorski and S. Gratton and A. Gregorio and A. Gruppuso and F. K. Hansen and D. Harrison and G. Helou and S. Henrot-Versille and D. Herranz and S. R. Hildebrandt and E. Hivon and M. Hobson and W. A. Holmes and W. Hovest and R. J. Hoyland and K. M. Huffenberger and A. H. Jaffe and G. Joncas and A. Jones and W. C. Jones and M. Juvela and E. Keihanen and R. Keskitalo and T. S. Kisner and R. Kneissl and L. Knox and H. Kurki-Suonio and G. Lagache and J. -M. Lamarre and A. Lasenby and R. J. Laureijs and C. R. Lawrence and S. Leach and R. Leonardi and C. Leroy and M. Linden-Vornle and F. J. Lockman and M. Lopez-Caniego and P. M. Lubin and J. F. Macias-Perez and C. J. MacTavish and B. Maffei and D. Maino and N. Mandolesi and R. Mann and M. Maris and D. J. Marshall and P. Martin and E. Martinez-Gonzalez and S. Masi and S. Matarrese and F. Matthai and P. Mazzotta and P. McGehee and P. R. Meinhold and A. Melchiorri and L. Mendes and A. Mennella and M. -A. Miville-Deschenes and A. Moneti and L. Montier and G. Morgante and D. Mortlock and D. Munshi and A. Murphy and P. Naselsky and F. Nati and P. Natoli and C. B. Netterfield and H. U. Norgaard-Nielsen and F. Noviello and D. Novikov and I. Novikov and I. J. O'Dwyer and S. Osborne and F. Pajot and R. Paladini and F. Pasian and G. Patanchon and O. Perdereau and L. Perotto and F. Perrotta and F. Piacentini and M. Piat and D. Pinheiro Goncalves and S. Plaszczynski and E. Pointecouteau and G. Polenta and N. Ponthieu and T. Poutanen and G. Prezeau and S. Prunet and J. -L. Puget and J. P. Rachen and W. T. Reach and M. Reinecke and C. Renault and S. Ricciardi and T. Riller and I. Ristorcelli and G. Rocha and C. Rosset and M. Rowan-Robinson and J. A. Rubino-Martin and B. Rusholme and M. Sandri and D. Santos and G. Savini and D. Scott and M. D. Seiffert and P. Shellard and G. F. Smoot and J. -L. Starck and F. Stivoli and V. Stolyarov and R. Stompor and R. Sudiwala and J. -F. Sygnet and J. A. Tauber and L. Terenzi and L. Toffolatti and M. Tomasi and J. -P. Torre and M. Tristram and J. Tuovinen and G. Umana and L. Valenziano and P. Vielva and F. Villa and N. Vittorio and L. A. Wade and B. D. Wandelt and A. Wilkinson and D. Yvon and A. Zacchei and A. Zonca},
journal= {arXiv preprint arXiv:1101.2036},
year = {2015}
}
Comments
30 pages, 22 figures, accepted for publication in A&A as a special issue for Planck early papers