Galactic cold cores: IV. Cold submillimetre sources: Catalogue and statistical analysis

J. Montillaud, M. Juvela, A. Rivera-Ingraham, J. Malinen, V. M. Pelkonen, I. Ristorcelli, L. Montier, D. J. Marshall, G. Marton, L. Pagani, L. Tóth, S. Zahorecz, N. Ysard, P. McGehee, R. Paladini, E. Falgarone, J. P. Bernard, F. Motte, A. Zavagno, Y. Doi

Research output: Contribution to journalArticle

20 Citations (Scopus)

Abstract

Context. For the project Galactic cold cores, Herschel photometric observations were carried out as a follow-up of cold regions of interstellar clouds previously identified with the Planck satellite. The aim of the project is to derive the physical properties of the population of cold sources and to study its connection to ongoing and future star formation. Aims. We build a catalogue of cold sources within the clouds in 116 fields observed with the Herschel PACS and SPIRE instruments. We wish to determine the general physical characteristics of the cold sources and to examine the correlations with their host cloud properties. Methods. From Herschel data, we computed colour temperature and column density maps of the fields. We estimated the distance to the target clouds and provide both uncertainties and reliability flags for the distances. The getsources multiwavelength source extraction algorithm was employed to build a catalogue of several thousand cold sources. Mid-infrared data were used, along with colour and position criteria, to separate starless and protostellar sources. We also propose another classification method based on submillimetre temperature profiles. We analysed the statistical distributions of the physical properties of the source samples. Results. We provide a catalogue of ∼4000 cold sources within or near star forming clouds, most of which are located either in nearby molecular complexes (≲ 1 kpc) or in star forming regions of the nearby galactic arms (∼2 kpc). About 70% of the sources have a size compatible with an individual core, and 35% of those sources are likely to be gravitationally bound. Significant statistical differences in physical properties are found between starless and protostellar sources, in column density versus dust temperature, mass versus size, and mass versus dust temperature diagrams. The core mass functions are very similar to those previously reported for other regions. On statistical grounds we find that gravitationally bound sources have higher background column densities (median Nbg(H2) ∼ 5 × 1021 cm-2) than unbound sources (median Nbg(H2) ∼ 3 × 1021 cm-2). These values of Nbg(H2) are higher for higher dust temperatures of the external layers of the parent cloud. However, only in a few cases do we find clear Nbg(H2) thresholds for the presence of cores. The dust temperatures of cloud external layers show clear variations with galactic location, as may the source temperatures. Conclusions. Our data support a more complex view of star formation than in the simple idea of a column density threshold. They show a clear influence of the surrounding UV-visible radiation on how cores distribute in their host clouds with possible variations on the Galactic scale.

Original languageEnglish
Article numberA92
JournalAstronomy and Astrophysics
Volume584
DOIs
Publication statusPublished - Dec 1 2015

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statistical analysis
catalogs
dust
physical property
temperature
cold region
physical properties
statistical distribution
cold
temperature profile
star formation
diagram
color
stars
thresholds
statistical distributions
temperature profiles
diagrams

Keywords

  • Catalogs
  • ISM: clouds
  • Stars: formation
  • Submillimeter: ISM

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Montillaud, J., Juvela, M., Rivera-Ingraham, A., Malinen, J., Pelkonen, V. M., Ristorcelli, I., ... Doi, Y. (2015). Galactic cold cores: IV. Cold submillimetre sources: Catalogue and statistical analysis. Astronomy and Astrophysics, 584, [A92]. https://doi.org/10.1051/0004-6361/201424063

Galactic cold cores : IV. Cold submillimetre sources: Catalogue and statistical analysis. / Montillaud, J.; Juvela, M.; Rivera-Ingraham, A.; Malinen, J.; Pelkonen, V. M.; Ristorcelli, I.; Montier, L.; Marshall, D. J.; Marton, G.; Pagani, L.; Tóth, L.; Zahorecz, S.; Ysard, N.; McGehee, P.; Paladini, R.; Falgarone, E.; Bernard, J. P.; Motte, F.; Zavagno, A.; Doi, Y.

In: Astronomy and Astrophysics, Vol. 584, A92, 01.12.2015.

Research output: Contribution to journalArticle

Montillaud, J, Juvela, M, Rivera-Ingraham, A, Malinen, J, Pelkonen, VM, Ristorcelli, I, Montier, L, Marshall, DJ, Marton, G, Pagani, L, Tóth, L, Zahorecz, S, Ysard, N, McGehee, P, Paladini, R, Falgarone, E, Bernard, JP, Motte, F, Zavagno, A & Doi, Y 2015, 'Galactic cold cores: IV. Cold submillimetre sources: Catalogue and statistical analysis', Astronomy and Astrophysics, vol. 584, A92. https://doi.org/10.1051/0004-6361/201424063
Montillaud J, Juvela M, Rivera-Ingraham A, Malinen J, Pelkonen VM, Ristorcelli I et al. Galactic cold cores: IV. Cold submillimetre sources: Catalogue and statistical analysis. Astronomy and Astrophysics. 2015 Dec 1;584. A92. https://doi.org/10.1051/0004-6361/201424063
Montillaud, J. ; Juvela, M. ; Rivera-Ingraham, A. ; Malinen, J. ; Pelkonen, V. M. ; Ristorcelli, I. ; Montier, L. ; Marshall, D. J. ; Marton, G. ; Pagani, L. ; Tóth, L. ; Zahorecz, S. ; Ysard, N. ; McGehee, P. ; Paladini, R. ; Falgarone, E. ; Bernard, J. P. ; Motte, F. ; Zavagno, A. ; Doi, Y. / Galactic cold cores : IV. Cold submillimetre sources: Catalogue and statistical analysis. In: Astronomy and Astrophysics. 2015 ; Vol. 584.
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abstract = "Context. For the project Galactic cold cores, Herschel photometric observations were carried out as a follow-up of cold regions of interstellar clouds previously identified with the Planck satellite. The aim of the project is to derive the physical properties of the population of cold sources and to study its connection to ongoing and future star formation. Aims. We build a catalogue of cold sources within the clouds in 116 fields observed with the Herschel PACS and SPIRE instruments. We wish to determine the general physical characteristics of the cold sources and to examine the correlations with their host cloud properties. Methods. From Herschel data, we computed colour temperature and column density maps of the fields. We estimated the distance to the target clouds and provide both uncertainties and reliability flags for the distances. The getsources multiwavelength source extraction algorithm was employed to build a catalogue of several thousand cold sources. Mid-infrared data were used, along with colour and position criteria, to separate starless and protostellar sources. We also propose another classification method based on submillimetre temperature profiles. We analysed the statistical distributions of the physical properties of the source samples. Results. We provide a catalogue of ∼4000 cold sources within or near star forming clouds, most of which are located either in nearby molecular complexes (≲ 1 kpc) or in star forming regions of the nearby galactic arms (∼2 kpc). About 70{\%} of the sources have a size compatible with an individual core, and 35{\%} of those sources are likely to be gravitationally bound. Significant statistical differences in physical properties are found between starless and protostellar sources, in column density versus dust temperature, mass versus size, and mass versus dust temperature diagrams. The core mass functions are very similar to those previously reported for other regions. On statistical grounds we find that gravitationally bound sources have higher background column densities (median Nbg(H2) ∼ 5 × 1021 cm-2) than unbound sources (median Nbg(H2) ∼ 3 × 1021 cm-2). These values of Nbg(H2) are higher for higher dust temperatures of the external layers of the parent cloud. However, only in a few cases do we find clear Nbg(H2) thresholds for the presence of cores. The dust temperatures of cloud external layers show clear variations with galactic location, as may the source temperatures. Conclusions. Our data support a more complex view of star formation than in the simple idea of a column density threshold. They show a clear influence of the surrounding UV-visible radiation on how cores distribute in their host clouds with possible variations on the Galactic scale.",
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T2 - IV. Cold submillimetre sources: Catalogue and statistical analysis

AU - Montillaud, J.

AU - Juvela, M.

AU - Rivera-Ingraham, A.

AU - Malinen, J.

AU - Pelkonen, V. M.

AU - Ristorcelli, I.

AU - Montier, L.

AU - Marshall, D. J.

AU - Marton, G.

AU - Pagani, L.

AU - Tóth, L.

AU - Zahorecz, S.

AU - Ysard, N.

AU - McGehee, P.

AU - Paladini, R.

AU - Falgarone, E.

AU - Bernard, J. P.

AU - Motte, F.

AU - Zavagno, A.

AU - Doi, Y.

PY - 2015/12/1

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N2 - Context. For the project Galactic cold cores, Herschel photometric observations were carried out as a follow-up of cold regions of interstellar clouds previously identified with the Planck satellite. The aim of the project is to derive the physical properties of the population of cold sources and to study its connection to ongoing and future star formation. Aims. We build a catalogue of cold sources within the clouds in 116 fields observed with the Herschel PACS and SPIRE instruments. We wish to determine the general physical characteristics of the cold sources and to examine the correlations with their host cloud properties. Methods. From Herschel data, we computed colour temperature and column density maps of the fields. We estimated the distance to the target clouds and provide both uncertainties and reliability flags for the distances. The getsources multiwavelength source extraction algorithm was employed to build a catalogue of several thousand cold sources. Mid-infrared data were used, along with colour and position criteria, to separate starless and protostellar sources. We also propose another classification method based on submillimetre temperature profiles. We analysed the statistical distributions of the physical properties of the source samples. Results. We provide a catalogue of ∼4000 cold sources within or near star forming clouds, most of which are located either in nearby molecular complexes (≲ 1 kpc) or in star forming regions of the nearby galactic arms (∼2 kpc). About 70% of the sources have a size compatible with an individual core, and 35% of those sources are likely to be gravitationally bound. Significant statistical differences in physical properties are found between starless and protostellar sources, in column density versus dust temperature, mass versus size, and mass versus dust temperature diagrams. The core mass functions are very similar to those previously reported for other regions. On statistical grounds we find that gravitationally bound sources have higher background column densities (median Nbg(H2) ∼ 5 × 1021 cm-2) than unbound sources (median Nbg(H2) ∼ 3 × 1021 cm-2). These values of Nbg(H2) are higher for higher dust temperatures of the external layers of the parent cloud. However, only in a few cases do we find clear Nbg(H2) thresholds for the presence of cores. The dust temperatures of cloud external layers show clear variations with galactic location, as may the source temperatures. Conclusions. Our data support a more complex view of star formation than in the simple idea of a column density threshold. They show a clear influence of the surrounding UV-visible radiation on how cores distribute in their host clouds with possible variations on the Galactic scale.

AB - Context. For the project Galactic cold cores, Herschel photometric observations were carried out as a follow-up of cold regions of interstellar clouds previously identified with the Planck satellite. The aim of the project is to derive the physical properties of the population of cold sources and to study its connection to ongoing and future star formation. Aims. We build a catalogue of cold sources within the clouds in 116 fields observed with the Herschel PACS and SPIRE instruments. We wish to determine the general physical characteristics of the cold sources and to examine the correlations with their host cloud properties. Methods. From Herschel data, we computed colour temperature and column density maps of the fields. We estimated the distance to the target clouds and provide both uncertainties and reliability flags for the distances. The getsources multiwavelength source extraction algorithm was employed to build a catalogue of several thousand cold sources. Mid-infrared data were used, along with colour and position criteria, to separate starless and protostellar sources. We also propose another classification method based on submillimetre temperature profiles. We analysed the statistical distributions of the physical properties of the source samples. Results. We provide a catalogue of ∼4000 cold sources within or near star forming clouds, most of which are located either in nearby molecular complexes (≲ 1 kpc) or in star forming regions of the nearby galactic arms (∼2 kpc). About 70% of the sources have a size compatible with an individual core, and 35% of those sources are likely to be gravitationally bound. Significant statistical differences in physical properties are found between starless and protostellar sources, in column density versus dust temperature, mass versus size, and mass versus dust temperature diagrams. The core mass functions are very similar to those previously reported for other regions. On statistical grounds we find that gravitationally bound sources have higher background column densities (median Nbg(H2) ∼ 5 × 1021 cm-2) than unbound sources (median Nbg(H2) ∼ 3 × 1021 cm-2). These values of Nbg(H2) are higher for higher dust temperatures of the external layers of the parent cloud. However, only in a few cases do we find clear Nbg(H2) thresholds for the presence of cores. The dust temperatures of cloud external layers show clear variations with galactic location, as may the source temperatures. Conclusions. Our data support a more complex view of star formation than in the simple idea of a column density threshold. They show a clear influence of the surrounding UV-visible radiation on how cores distribute in their host clouds with possible variations on the Galactic scale.

KW - Catalogs

KW - ISM: clouds

KW - Stars: formation

KW - Submillimeter: ISM

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