Comparing Submillimeter Polarized Emission with Near-infrared Polarization of Background Stars for the Vela C Molecular Cloud
We present a large-scale combination of near-infrared (near-IR) interstellar polarization data from background starlight with polarized emission data at submillimeter wavelengths for the Vela C molecular cloud. The near-IR data consist of more than 6700 detections probing a range of visual extinctio...
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American Astronomical Society
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ftcaltechauth:oai:authors.library.caltech.edu:75224 2023-05-15T13:55:46+02:00 Comparing Submillimeter Polarized Emission with Near-infrared Polarization of Background Stars for the Vela C Molecular Cloud Santos, Fábio P. Moncelsi, Lorenzo 2017-03-10 application/pdf https://authors.library.caltech.edu/75224/ https://authors.library.caltech.edu/75224/1/Santos_2017_ApJ_837_161.pdf https://authors.library.caltech.edu/75224/2/1605.08522%20%282%29.pdf https://resolver.caltech.edu/CaltechAUTHORS:20170320-071918564 en eng American Astronomical Society https://authors.library.caltech.edu/75224/1/Santos_2017_ApJ_837_161.pdf https://authors.library.caltech.edu/75224/2/1605.08522%20%282%29.pdf Santos, Fábio P. and Moncelsi, Lorenzo (2017) Comparing Submillimeter Polarized Emission with Near-infrared Polarization of Background Stars for the Vela C Molecular Cloud. Astrophysical Journal, 837 (2). Art. No. 161. ISSN 1538-4357. doi:10.3847/1538-4357/aa62a7. https://resolver.caltech.edu/CaltechAUTHORS:20170320-071918564 <https://resolver.caltech.edu/CaltechAUTHORS:20170320-071918564> other Article PeerReviewed 2017 ftcaltechauth https://doi.org/10.3847/1538-4357/aa62a7 2021-11-18T18:41:15Z We present a large-scale combination of near-infrared (near-IR) interstellar polarization data from background starlight with polarized emission data at submillimeter wavelengths for the Vela C molecular cloud. The near-IR data consist of more than 6700 detections probing a range of visual extinctions between 2 and 20 mag in and around the cloud. The submillimeter data were collected in Antarctica by the Balloon-borne Large Aperture Submillimeter Telescope for Polarimetry. This is the first direct combination of near-IR and submillimeter polarization data for a molecular cloud aimed at measuring the "polarization efficiency ratio" R_(eff), a quantity that is expected to depend only on grain-intrinsic physical properties. It is defined as p_(500)/(pt_TV), where p 500 and p I are polarization fractions at 500 µm and the I band, respectively, and t_V is the optical depth. To ensure that the same column density of material is producing both polarization from emission and from extinction, we conducted a careful selection of near-background stars using 2MASS, Herschel, and Planck data. This selection excludes objects contaminated by the Galactic diffuse background material as well as objects located in the foreground. Accounting for statistical and systematic uncertainties, we estimate an average R_(eff) value of 2.4 ± 0.8, which can be used to test the predictions of dust grain models designed for molecular clouds when such predictions become available. The ratio R_(eff) appears to be relatively flat as a function of the cloud depth for the range of visual extinctions probed. Article in Journal/Newspaper Antarc* Antarctica Caltech Authors (California Institute of Technology) Starlight ENVELOPE(64.483,64.483,-70.200,-70.200) The Astrophysical Journal 837 2 161 |
institution |
Open Polar |
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Caltech Authors (California Institute of Technology) |
op_collection_id |
ftcaltechauth |
language |
English |
description |
We present a large-scale combination of near-infrared (near-IR) interstellar polarization data from background starlight with polarized emission data at submillimeter wavelengths for the Vela C molecular cloud. The near-IR data consist of more than 6700 detections probing a range of visual extinctions between 2 and 20 mag in and around the cloud. The submillimeter data were collected in Antarctica by the Balloon-borne Large Aperture Submillimeter Telescope for Polarimetry. This is the first direct combination of near-IR and submillimeter polarization data for a molecular cloud aimed at measuring the "polarization efficiency ratio" R_(eff), a quantity that is expected to depend only on grain-intrinsic physical properties. It is defined as p_(500)/(pt_TV), where p 500 and p I are polarization fractions at 500 µm and the I band, respectively, and t_V is the optical depth. To ensure that the same column density of material is producing both polarization from emission and from extinction, we conducted a careful selection of near-background stars using 2MASS, Herschel, and Planck data. This selection excludes objects contaminated by the Galactic diffuse background material as well as objects located in the foreground. Accounting for statistical and systematic uncertainties, we estimate an average R_(eff) value of 2.4 ± 0.8, which can be used to test the predictions of dust grain models designed for molecular clouds when such predictions become available. The ratio R_(eff) appears to be relatively flat as a function of the cloud depth for the range of visual extinctions probed. |
format |
Article in Journal/Newspaper |
author |
Santos, Fábio P. Moncelsi, Lorenzo |
spellingShingle |
Santos, Fábio P. Moncelsi, Lorenzo Comparing Submillimeter Polarized Emission with Near-infrared Polarization of Background Stars for the Vela C Molecular Cloud |
author_facet |
Santos, Fábio P. Moncelsi, Lorenzo |
author_sort |
Santos, Fábio P. |
title |
Comparing Submillimeter Polarized Emission with Near-infrared Polarization of Background Stars for the Vela C Molecular Cloud |
title_short |
Comparing Submillimeter Polarized Emission with Near-infrared Polarization of Background Stars for the Vela C Molecular Cloud |
title_full |
Comparing Submillimeter Polarized Emission with Near-infrared Polarization of Background Stars for the Vela C Molecular Cloud |
title_fullStr |
Comparing Submillimeter Polarized Emission with Near-infrared Polarization of Background Stars for the Vela C Molecular Cloud |
title_full_unstemmed |
Comparing Submillimeter Polarized Emission with Near-infrared Polarization of Background Stars for the Vela C Molecular Cloud |
title_sort |
comparing submillimeter polarized emission with near-infrared polarization of background stars for the vela c molecular cloud |
publisher |
American Astronomical Society |
publishDate |
2017 |
url |
https://authors.library.caltech.edu/75224/ https://authors.library.caltech.edu/75224/1/Santos_2017_ApJ_837_161.pdf https://authors.library.caltech.edu/75224/2/1605.08522%20%282%29.pdf https://resolver.caltech.edu/CaltechAUTHORS:20170320-071918564 |
long_lat |
ENVELOPE(64.483,64.483,-70.200,-70.200) |
geographic |
Starlight |
geographic_facet |
Starlight |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_relation |
https://authors.library.caltech.edu/75224/1/Santos_2017_ApJ_837_161.pdf https://authors.library.caltech.edu/75224/2/1605.08522%20%282%29.pdf Santos, Fábio P. and Moncelsi, Lorenzo (2017) Comparing Submillimeter Polarized Emission with Near-infrared Polarization of Background Stars for the Vela C Molecular Cloud. Astrophysical Journal, 837 (2). Art. No. 161. ISSN 1538-4357. doi:10.3847/1538-4357/aa62a7. https://resolver.caltech.edu/CaltechAUTHORS:20170320-071918564 <https://resolver.caltech.edu/CaltechAUTHORS:20170320-071918564> |
op_rights |
other |
op_doi |
https://doi.org/10.3847/1538-4357/aa62a7 |
container_title |
The Astrophysical Journal |
container_volume |
837 |
container_issue |
2 |
container_start_page |
161 |
_version_ |
1766262602565943296 |