A catalogue of dense cores and young stellar objects in the Lupus complex based on Herschel Gould Belt Survey observations

Abstract

The Herschel Gould Belt Survey key project mapped the bulk of nearby star-forming molecular clouds in five far-infrared bands with the aim of compiling complete census of prestellar cores and young, embedded protostars. In this paper, we present the catalogue of the dense cores and YSOs/protostars extracted from the Herschel maps of the Lupus I, III, and IV molecular clouds. The physical properties of the detected objects were derived by fitting their spectral energy distributions. A total of 532 dense cores, out of which 103 are presumably prestellar in nature, and 38 YSOs/protostars have been detected in the three clouds. Almost all the prestellar cores are associated with filaments against only about one third of the unbound cores and YSOs/protostars. Prestellar core candidates are found even in filaments that are on average thermally sub-critical and over a background column density lower than that measured in other star forming regions so far. The core mass function of the prestellar cores peaks between 0.2 and 0.3 solar masses and it is compatible with the log-normal shape found in other regions. Herschel data reveal several, previously undetected, protostars and new candidates of Class 0 and Class II with transitional disks. We estimate the evolutionary status of the YSOs/protostars using two independent indicators: the $\alpha$ index and the fitting of the spectral energy distribution from near- to far-infrared wavelengths. For 70% of the objects, the evolutionary stages derived with the two methods are in agreement. Lupus is confirmed to be a very low-mass star-forming region, both in terms of the prestellar condensations and of the diffuse medium. Noticeably, in the Lupus clouds we have found star formation activity associated with interstellar medium at low column density, usually quiescent in other (more massive) star forming regions.

arXiv comment25 pages, 15 ifgures

References in corpus (54)

• Herschel Space Observatory - An ESA facility for far-infrared and submillimetre astronomy
• The Photodetector Array Camera and Spectrometer (PACS) on the Herschel Space Observatory
• The Herschel-SPIRE instrument and its in-flight performance
• The Spitzer c2d Legacy Results: Star Formation Rates and Efficiencies; Evolution and Lifetimes
• From filamentary clouds to prestellar cores to the stellar IMF: Initial highlights from the Herschel Gould Belt survey
• The distance to the Orion Nebula
• Characterizing interstellar filaments with Herschel in IC5146
• On the Star Formation Rates in Molecular Clouds
• Gaia Data Release 2: using Gaia parallaxes
• Herschel view of the Taurus B211/3 filament and striations: Evidence of filamentary growth?
• Systematic Molecular Differentiation in Starless Cores
• The mass function of dense molecular cores and the origin of the IMF
• X-Shooter spectroscopy of young stellar objects in Lupus: Accretion properties of class II and transitional objects
• The initial mass function : from Salpeter 1955 to 2005
• The Mass Distribution and Lifetime of Prestellar Cores in Perseus, Serpens, and Ophiuchus
• Observing the gas temperature drop in the high-density nucleus of L 1544
• The Turbulent Shock Origin of Proto--Stellar Cores
• The Formation and Destruction of Molecular Clouds and Galactic Star Formation
• The Large and Small Scale Structures of Dust in the Star-Forming Perseus Molecular Cloud
• An Extinction Threshold for Protostellar Cores in Ophiuchus
• A census of dense cores in the Aquila cloud complex: SPIRE/PACS observations from the Herschel Gould Belt survey
• The Herschel-PACS photometer calibration: Point-source flux calibration for scan maps
• A multi-scale, multi-wavelength source extraction method: getsources
• The Spitzer c2d Survey of Large, Nearby, Interstellar Clouds. XI. Lupus Observed With IRAC and MIPS
• Reconstructing the density and temperature structure of prestellar cores from $Herschel$ data: A case study for B68 and L1689B
• Formation and evolution of interstellar filaments; Hints from velocity dispersion measurements
• Source extraction and photometry for the far-infrared and sub-millimeter continuum in the presence of complex backgrounds
• Rapid Molecular Cloud and Star Formation: Mechanisms and Movies
• The identification of filaments on far infrared and submillimiter images. Morphology, physical conditions and relation with star formation of filamentary structure
• A census of dense cores in the Taurus L1495 cloud from the Herschel Gould Belt Survey
• Flux calibration of the Herschel-SPIRE photometer
• The structure and stability of molecular cloud cores in external radiation fields
• The first Hi-GAL observations of the outer Galaxy: a look to star formation in the third Galactic quadrant in the longitude range 216.5 < l < 225.5
• A modular set of synthetic spectral energy distributions for young stellar objects
• First results from the Herschel Gould Belt Survey in Taurus
• A multi-scale filament extraction method: getfilaments
• Two Mass Distributions in the L 1641 Molecular Clouds: The Herschel connection of Dense Cores and Filaments in Orion A
• Schmidt's Conjecture and Star Formation in Molecular Clouds
• Dense Cores in Perseus: The Influence of Stellar Content and Cluster Environment
• The Herschel view of the on-going star formation in the Vela-C molecular cloud
• The dense cores and filamentary structure of the molecular cloud in Corona Australis. Herschel SPIRE and PACS observations from the Herschel Gould Belt Survey
• A kinematic study and membership analysis of the Lupus star-forming region
• Spectroscopic properties of Young Stellar Objects in the Lupus Molecular Clouds
• Recent star formation in the Lupus clouds as seen by Herschel
• Filaments in the Lupus molecular clouds
• Identification of new transitional disk candidates in Lupus with Herschel
• Far-infrared observations of a massive cluster forming in the Monoceros R2 filament hub
• Fitting density models to observational data - The local Schmidt law in molecular clouds
• The Green Bank Ammonia Survey: Observations of Hierarchical Dense Gas Structures in Cepheus-L1251
• Multi-line spectral imaging of dense cores in the Lupus molecular cloud
• Uncertainties and biases of source masses derived from fits of integrated fluxes or image intensities
• Large-Scale CO Maps of the Lupus Molecular Cloud Complex
• Squeezed between shells? On the origin of the Lupus I molecular cloud. APEX/LABOCA, Herschel, and Planck observations
• The Herschel PACS photometer calibration - A time dependent flux calibration for the PACS chopped point-source photometry AOT mode

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• The Herschel view of the dense core population in the Ophiuchus molecular cloud
• Probing accretion of ambient cloud material into the Taurus B211/B213 filament
• Zooming in on Individual Star Formation: Low- and High-mass Stars
• Understanding star formation in molecular clouds IV. Column density PDFs from quiescent to massive molecular clouds
• Star-Gas Surface Density Correlations in Twelve Nearby Molecular Clouds I: Data Collection and Star-Sampled Analysis
• The Origin of the Stellar Mass Distribution and Multiplicity
• Physical properties of the ambient medium and of dense cores in the Perseus star-forming region derived from Herschel Gould Belt Survey observations
• Herschel Gould Belt Survey Observations of Dense Cores in the Cepheus Flare Clouds
• A Gaia Survey for Young Stars Associated with the Lupus Clouds
• The census of dense cores in the Serpens region from the Herschel Gould Belt Survey
• What happened before? -- The disks around the precursors of young Herbig Ae/Be stars
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• The ALMA Survey of Gas Evolution of PROtoplanetary Disks (AGE-PRO): III. Dust and Gas Disk Properties in the Lupus Star-forming Region
• Outflows, envelopes, and disks as evolutionary indicators in Lupus YSOs
• 2MASS J15491331-3539118: a new low-mass wide companion of the GQ Lup system
• Catalogue of High Protostellar Surface Density Regions in Nearby Embedded Clusters
• A Random Forest Approach to Identifying Young Stellar Object Candidates in the Lupus Star-Forming Region
• Understanding the Star Formation Efficiency in Dense Gas: Initial Results from the CAFFEINE Survey with ArTéMiS
• Characterization of dense Planck clumps observed with Herschel and SCUBA-2
• Dust emission, extinction, and scattering in LDN 1642
• Linking High- and Low-Mass Star Formation: Observation-Based Continuum Modelling and Physical Conditions
• SEDBYS: A python-based SED Builder for Young Stars
• Turbulence and its connection to episodic accretion in binary YSOs
• Non-ideal magnetohydrodynamics of self-gravitating filaments
• Robustness of Synthetic Observations in Producing Observed Core Properties: Predictions for the TolTEC Clouds to Cores Legacy Survey
• The JCMT Gould Belt Survey Complete Core Catalogue: Core mass function variations between nearby molecular clouds
• ALMA Datacubes and Continuum Maps of the Irradiated Western Wall in Carina
• Prestellar Cores in Turbulent Clouds: Properties of Critical Cores
• A low-mass hub-filament with double centre revealed in NGC2071-North
• The kinematics of the magnetised protostellar core IRAS15398-3359
• Hunting pre-stellar cores with APEX: overview
• New members of the Lupus I cloud based on Gaia astrometry Physical and accretion properties from X-Shooter spectra
• On volume density and star formation in nearby molecular clouds