Please use this identifier to cite or link to this item:
http://hdl.handle.net/20.500.12386/28824
DC Field | Value | Language |
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dc.contributor.author | Roy, A. | en_US |
dc.contributor.author | André, Ph. | en_US |
dc.contributor.author | Arzoumanian, D. | en_US |
dc.contributor.author | Miville-Deschênes, M. -A. | en_US |
dc.contributor.author | Könyves, V. | en_US |
dc.contributor.author | Schneider, N. | en_US |
dc.contributor.author | PEZZUTO, Stefano | en_US |
dc.contributor.author | Palmeirim, P. | en_US |
dc.contributor.author | Kirk, J. M. | en_US |
dc.date.accessioned | 2020-12-14T11:01:15Z | - |
dc.date.available | 2020-12-14T11:01:15Z | - |
dc.date.issued | 2019 | en_US |
dc.identifier.issn | 0004-6361 | en_US |
dc.identifier.uri | http://hdl.handle.net/20.500.12386/28824 | - |
dc.description.abstract | Context. Herschel observations of interstellar clouds support a paradigm for star formation in which molecular filaments play a central role. One of the foundations of this paradigm is the finding, based on detailed studies of the transverse column density profiles observed with Herschel, that nearby molecular filaments share a common inner width of ∼0.1 pc. The existence of a characteristic filament width has been recently questioned, however, on the grounds that it seems inconsistent with the scale-free nature of the power spectrum of interstellar cloud images. <BR /> Aims: In an effort to clarify the origin of this apparent discrepancy, we examined the power spectra of the Herschel/SPIRE 250 μm images of the Polaris, Aquila, and Taurus-L1495 clouds in detail and performed a number of simple numerical experiments by injecting synthetic filaments in both the Herschel images and synthetic background images. <BR /> Methods: We constructed several populations of synthetic filaments of 0.1 pc width with realistic area filling factors (A<SUB>fil</SUB>) and distributions of column density contrasts (δ<SUB>c</SUB>). After adding synthetic filaments to the original Herschel images, we recomputed the image power spectra and compared the results with the original, essentially scale-free power spectra. We used the χ<SUP>2</SUP><SUB>variance</SUB> of the residuals between the best power-law fit and the output power spectrum in each simulation as a diagnostic of the presence (or absence) of a significant departure from a scale-free power spectrum. <BR /> Results: We find that χ<SUP>2</SUP><SUB>variance</SUB> depends primarily on the combined parameter δ<SUP>2</SUP><SUB>2</SUB> A<SUB>fil</SUB>. According to our numerical experiments, a significant departure from a scale-free behavior and thus the presence of a characteristic filament width become detectable in the power spectrum when δ<SUP>2</SUP><SUB>2</SUB> A<SUB>fil</SUB> ⪆ 0.1 for synthetic filaments with Gaussian profiles and δ<SUP>2</SUP><SUB>2</SUB> A<SUB>fil</SUB> ⪆ 0.4 for synthetic filaments with Plummer-like density profiles. Analysis of the real Herschel 250 μm data suggests that δ<SUP>2</SUP><SUB>2</SUB> A<SUB>fil</SUB> is ∼0.01 in the case of the Polaris cloud and ∼0.016 in the Aquila cloud, significantly below the fiducial detection limit of δ<SUP>2</SUP><SUB>2</SUB> A<SUB>fil</SUB> ∼ 0.1 in both cases. In both clouds, the observed filament contrasts and area filling factors are such that the filamentary structure contributes only ∼1/5 of the power in the image power spectrum at angular frequencies where an effect of the characteristic filament width is expected. <BR /> Conclusions: We conclude that the essentially scale-free power spectra of Herschel images remain consistent with the existence of a characteristic filament width ∼0.1 pc and do not invalidate the conclusions drawn from studies of the filament profiles. | en_US |
dc.language.iso | eng | en_US |
dc.title | How the power spectrum of dust continuum images may hide the presence of a characteristic filament width | en_US |
dc.type | Article | - |
dc.identifier.doi | 10.1051/0004-6361/201832869 | en_US |
dc.identifier.scopus | 2-s2.0-85086595538 | en_US |
dc.identifier.isi | 000471641800006 | en_US |
dc.identifier.url | https://www.aanda.org/articles/aa/full_html/2019/06/aa32869-18/aa32869-18.html | en_US |
dc.relation.medium | STAMPA | en_US |
dc.relation.volume | 626 | en_US |
dc.relation.firstpage | A76 | en_US |
dc.type.referee | REF_1 | en_US |
dc.description.international | sì | en_US |
dc.relation.scientificsector | FIS/05 - ASTRONOMIA E ASTROFISICA | en_US |
dc.relation.journal | ASTRONOMY & ASTROPHYSICS | en_US |
dc.type.miur | 262 Articolo in rivista | - |
dc.identifier.adsbibcode | 2019A&A...626A..76R | en_US |
dc.relation.ercsector | ERC sectors::Physical Sciences and Engineering::PE9 Universe sciences: astro-physics/chemistry/biology; solar systems; stellar, galactic and extragalactic astronomy, planetary systems, cosmology, space science, instrumentation::PE9_6 Stars and stellar systems | en_US |
dc.description.apc | no | en_US |
dc.description.oa | 1 – prodotto con file in versione Open Access (allegare il file al passo 5-Carica) | en_US |
item.openairecristype | http://purl.org/coar/resource_type/c_18cf | - |
item.openairetype | Article | - |
item.languageiso639-1 | en | - |
item.cerifentitytype | Publications | - |
item.grantfulltext | open | - |
item.fulltext | With Fulltext | - |
crisitem.author.dept | IAPS Roma | - |
crisitem.author.orcid | 0000-0001-7852-1971 | - |
crisitem.journal.journalissn | 0004-6361 | - |
crisitem.journal.ance | E016240 | - |
Appears in Collections: | 1.01 Articoli in rivista |
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File | Description | Size | Format | |
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aa32869-18-compr.pdf | Pdf editoriale | 1.26 MB | Adobe PDF | View/Open |
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