Growing evidence for a core formation threshold traced in Herschel1 Gould Belt survey clouds. Issue 9 (November 2013)

• Record Type: Journal Article
• Authors: Könyves, V.; André, Ph.; Schneider, N.; Palmeirim, P.; Arzoumanian, D.; Men'shchikov, A.; Barnaföldi, Gergely Gábor; Forgás‐Dajka, Emese; Kiss, Csaba; Verebélyi, Erika
• Is Part Of: Astronomische Nachrichten. Volume 334:Issue 9(2013)
• Page Start: 908
• Page End: 911
• Publication Date: 2013-11
• Subjects: Astronomy -- Periodicals; 520.5
• DOI: 10.1002/asna.201211956
• Languages: English
• ISSNs: 0004-6337

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>It has already been suggested that a threshold in column density – or in visual extinction – may need to be exceeded to form dense cores and then protostars. Based on <italic>Herschel</italic> Gould Belt survey results in the Aquila and Orion B molecular cloud complexes we observe clear connection between the locations of the detected prestellar cores and their background column density values. This finding appears to support a core formation scenario where such threshold corresponds to the extinction above which interstellar filaments become gravitationally unstable and fragment into cores. In these two actively star‐forming regions we find the vast majority of the gravitationally bound prestellar cores above a high column density of about (6–7) × 10²¹ cm^–2 (<italic>AV</italic> ∼ 6–7). This limit similarly appears in the column density probability distribution function (PDF) of the regions as well. The spatial distribution of the protostars and young stellar objects (YSOs) also shows a tight connection with the densest sites of both clouds, as more than 70 % of them appear above the mentioned <italic>AV</italic> thresholds. (© 2013 WILEY‐VCH Verlag GmbH &amp; Co. KGaA, Weinheim)</p> </abstract>