Filamentary structures and compact objects in the Aquila and Polaris clouds observed by Herschel

Our PACS and SPIRE images of the Aquila Rift and part of the Polaris Flare regions, taken during the science demonstration phase of Herschel discovered fascinating, omnipresent filamentary structures that appear to be physically related to compact cores. We briefly describe a new multi-scale, multi-wavelength source extraction method used to detect objects and measure their parameters in our Herschel images. All of the extracted starless cores (541 in Aquila and 302 in Polaris) appear to form in the long and very narrow filaments. With its combination of the far-IR resolution and sensitivity, Herschel directly reveals the filaments in which the dense cores are embedded; the filaments are resolved and have deconvolved widths of 35 arcsec in Aquila and 59 arcsec in Polaris (9000 AU in both regions). Our first results of observations with Herschel enable us to suggest that in general dense cores may originate in a process of fragmentation of complex networks of long, thin filaments, likely formed as a result of an interplay between gravity, interstellar turbulence, and magnetic fields. To unravel the roles of the processes, one has to obtain additional kinematic and polarization information; these follow-up observations are planned.

[1]  S. Ott,et al.  Herschel Space Observatory - An ESA facility for far-infrared and submillimetre astronomy , 2010, 1005.5331.

[2]  S. J. Liu,et al.  Herschel : the first science highlights Special feature L etter to the E ditor The Herschel-SPIRE instrument and its in-flight performance , 2010 .

[3]  H. Roussel,et al.  In-flight calibration of the Herschel-SPIRE instrument , 2010, 1005.5073.

[4]  M. Sauvage,et al.  Clouds, filaments, and protostars: TheHerschel Hi-GAL Milky Way , 2010, 1005.3317.

[5]  M. Sauvage,et al.  The Aquila prestellar core population revealed by Herschel , 2010, 1005.2981.

[6]  M. Sauvage,et al.  A Herschel study of the properties of starless cores in the Polaris Flare dark cloud region using PACS and SPIRE , 2010, 1005.2519.

[7]  M. Sauvage,et al.  Special Feature the Herschel First Look at Protostars in the Aquila Rift , 2022 .

[8]  Zhi-Yun Li,et al.  Magnetically Regulated Star Formation in Three Dimensions: The Case of the Taurus Molecular Cloud Complex , 2008, 0804.4201.

[9]  P. Ocvirk,et al.  Bimodal gas accretion in the Horizon–MareNostrum galaxy formation simulation , 2008, 0803.4506.

[10]  Gopal Narayanan,et al.  Large-Scale Structure of the Molecular Gas in Taurus Revealed by High Linear Dynamic Range Spectral Line Mapping , 2008, 0802.2206.

[11]  Thomas Henning,et al.  The Photodetector Array Camera and Spectrometer (PACS) for the Herschel Space Observatory , 2004, Astronomical Telescopes + Instrumentation.

[12]  S. Bontemps,et al.  The earliest phases of high-mass star formation: a 3 square degree millimeter continuum mapping of Cygnus X , 2007, 0708.2774.

[13]  V. Straižys,et al.  Interstellar extinction in the direction of the Aquila Rift , 2003, astro-ph/0303099.

[14]  Daniel Durand,et al.  Astronomical Data Analysis Software and Systems XI , 2009 .

[15]  Jean-Luc Starck,et al.  Astronomical image and data analysis , 2002 .

[16]  C. D. Wilson,et al.  MAGNETIC FIELDS IN STAR-FORMING MOLECULAR CLOUDS. II. THE DEPOLARIZATION EFFECT IN THE OMC-3 FILAMENT OF ORION A , 2001 .

[17]  M. Juvela,et al.  The Turbulent Shock Origin of Proto-Stellar Cores , 2000, astro-ph/0011122.

[18]  J. Alves,et al.  Infrared Extinction and the Structure of the IC 5146 Dark Cloud , 1999 .

[19]  Helical fields and filamentary molecular clouds — I , 1999, astro-ph/9901096.

[20]  S. Miyama,et al.  An Origin of Filamentary Structure in Molecular Clouds , 1998 .

[21]  J. Bally,et al.  JCMT/SCUBA Submillimeter Wavelength Imaging of the Integral-shaped Filament in Orion , 1998 .

[22]  E. Bertin,et al.  SExtractor: Software for source extraction , 1996 .

[23]  Leo Blitz,et al.  DETERMINING STRUCTURE IN MOLECULAR CLOUDS , 1994 .

[24]  P. Thaddeus,et al.  The Polaris Flare - Extensive molecular gas near the north celestial pole , 1990 .

[25]  J. Stutzki,et al.  High spatial resolution isotopic CO and CS observations of M17 SW - The clumpy structure of the molecular cloud core , 1989 .

[26]  B. Elmegreen,et al.  A catalog of dark globular filaments. , 1979 .

[27]  Alvy Ray Smith,et al.  Tint fill , 1979, SIGGRAPH.

[28]  J. Ostriker The Equilibrium of Polytropic and Isothermal Cylinders. , 1964 .