Predicted colors and flux densities of protostars in the<i>Herschel</i>PACS and SPIRE filters

Ali, B.; Tobin, John J.; Fischer, William J.; Poteet, C. A.; Megeath, S. Thomas; Allen, Lori; Hartmann, L.; Calvet, Nuria; Furlan, Elise; Osorio, M. R. Zapatero

doi:10.1051/0004-6361/201014599

Cited by 25 publications

(35 citation statements)

References 13 publications

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“…These color ranges are consistent with the PACS/SPIRE colors predicted in Ali et al (2010) for protostars and with the PACS colors of the sample of young very low-mass stars and BDs published in Harvey et al (2012b). PACS/SPIRE colors of reddened photospheres are close to zero regardless of the assumed effective temperature and are unlikely to contaminate the YSO locus defined above, which is restricted to log(F 250 /F 350 ) 0.05, even assuming a very high extinction (i.e., A V = 100 mag).…”

Section: Exploring the Yso Locus In Pacs/spire Color-color Diagramssupporting

confidence: 90%

“…Like Chamaeleon, Serpens is one of the clouds observed within the frame of the HGBS; the Herschel fluxes for the YSOs in this cloud were retrieved from the catalog obtained in Bressert et al (2013), and a paper focused on this population is in preparation (Spezzi et al, in prep.). We also used, for comparison purposes, the PACS fluxes of ∼50 young very low mass stars and brown dwarfs (BDs) published in Harvey et al (2012b) and the predicted colors and flux densities of protostars in PACS and SPIRE filters in Ali et al (2010); these colors are based on a grid of 20 160 model SEDs of low-mass protostars obtained by considering emission from four main components (a central object, a flared disk, a rotating collapsing envelope and a bipolar cavity) and varying their configuration parameters. (Winston et al 2012) and Serpens (Bressert et al 2013), respectively.…”

Section: Exploring the Yso Locus In Pacs/spire Color-color Diagramsmentioning

confidence: 99%

“…The solid and dot-dashed lines in the middle and right panels indicate the loci of galaxies in the Herschel-ATLAS catalog and AGNs in the Herschel-HerMES survey, respectively. In the left panel, the gray-filled area is the protostar locus predicted in Ali et al (2010), while the arrow-head line displays the log(F 70 /F 160 ) color range of the very low-mass stars and brown dwarfs in Harvey et al (2012b).…”

Section: Exploring the Yso Locus In Pacs/spire Color-color Diagramsmentioning

confidence: 99%

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TheHerschelGould Belt Survey in Chamaeleon II

Spezzi

Cox

Prusti

et al. 2013

A&A

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Context. We report on the Herschel Gould Belt survey (HGBS) of the Chamaeleon II (Cha II) star-forming region, focusing on the detection of Class I to III young stellar objects (YSOs). Aims. We aim at characterizing the circumstellar material around these YSOs and at understanding which disk parameters are most likely constrained by the new HGBS data, which are expected to be crucial for studying the transition from optically thick disks to evolved debris-type disks. Methods. We recovered 29 of the 63 known YSOs in Cha II with a detection in at least one of the PACS/SPIRE pass-bands: 3 Class I YSOs (i.e.,100%), 1 flat source (i.e., 50%), 21 Class II objects (i.e., 55%), 3 Class III objects (i.e, 16%), and the unclassified farinfrared source IRAS 12522-7640. We explored PACS/SPIRE colors of this sample and modeled their spectral energy distributions (SEDs) from the optical to Herschel's wavelengths with the RADMC-2D radiative transfer code. Results. We find that YSO colors are typically confined to the following ranges: −0.7 log (F 70 /F 160 ) 0.5, −0.5 log (F 160 /F 250 ) 0.6, 0.05 log(F 250 /F 350 ) 0.25 and −0.1 log (F 350 /F 500 ) 0.5. These color ranges are expected to be only marginally contaminated by extragalactic sources and field stars and, hence, provide a useful YSO selection tool when applied together. We were able to model the SED of 26 of the 29 detected YSOs. We discuss the degeneracy/limitations of our SED fitting results and adopted the Bayesian method to estimate the probability of different values for the derived disk parameters. The Cha II YSOs present typical disk inner radii 0.1 AU, as previously estimated in the literature on the basis of Spitzer data. Our probability analysis shows that, thanks to the new Herschel data, the lower limits to the disk mass (M disk ) and characteristic radius (R C ) are well constrained, while the flaring angle (1 + φ) is only marginally constrained. The lower limit to R C is typically around 50 AU. The lower limits to M disk are proportional to the stellar masses with a typical 0.3% ratio, i.e., in the range estimated in the literature for young Class II stars and brown dwarfs across a broad range of stellar masses. The estimated flaring angles, although very uncertain, point toward very flat disks (1 + φ 1.2), as found for low-mass M-type YSO samples in other star-forming regions. Thus, our results support the idea that disk properties show a dependence on stellar properties.

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Section: Exploring the Yso Locus In Pacs/spire Color-color Diagramssupporting

confidence: 90%

Section: Exploring the Yso Locus In Pacs/spire Color-color Diagramsmentioning

confidence: 99%

Section: Exploring the Yso Locus In Pacs/spire Color-color Diagramsmentioning

confidence: 99%

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TheHerschelGould Belt Survey in Chamaeleon II

Spezzi

Cox

Prusti

et al. 2013

A&A

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“…12 http://cassis.astro.cornell.edu/atlas/ 13 http://sha.ipac.caltech.edu/ The grid is a refinement of the one described in Ali et al (2010). The central source has fixed properties, with a radius of R * = 2.09 R , a mass of M * = 0.5 M , and an effective temperature of 4000 K. In embedded low-mass protostars, reprocessing of luminosity by the envelope generally destroys information about the central star, so this simplification does not reduce the range of SED shapes in the grid.…”

Section: Fitting With a Grid Of 3600 Modelsmentioning

confidence: 99%

“…The source appears in the catalog for the Herschel Orion Protostar Survey (HOPS; Fischer et al 2010;Stanke et al 2010;Ali et al 2010), the HOPS, an open-time key program of the Herschel Space Observatory. The goal of HOPS is to obtain 70 and 160 μm imaging and 50-200 μm spectra of protostars in the Orion molecular clouds that were identified with Spitzer Space Telescope photometry by Megeath et al (2012).…”

Section: Introductionmentioning

confidence: 99%

MULTIWAVELENGTH OBSERVATIONS OF V2775 Ori, AN OUTBURSTING PROTOSTAR IN L 1641: EXPLORING THE EDGE OF THE FU ORIONIS REGIME

Fischer

Megeath

Tobin

et al. 2012

ApJ

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Individual outbursting young stars are important laboratories for studying the physics of episodic accretion and the extent to which this phenomenon can explain the luminosity distribution of protostars. We present new and archival data for V2775 Ori (HOPS 223), a protostar in the L 1641 region of the Orion molecular clouds that was discovered by Caratti o Garatti et al. to have recently undergone an order-of-magnitude increase in luminosity. Our near-infrared spectra of the source have strong blueshifted He i λ10830 absorption, strong H 2 O and CO absorption, and no H i emission, all typical of FU Orionis sources. With data from the Infrared Telescope Facility, the Two Micron All Sky Survey, the Hubble Space Telescope, Spitzer, the Wide-field Infrared Survey Explorer, Herschel, and the Atacama Pathfinder Experiment that span from 1 to 70 μm pre-outburst and from 1 to 870 μm post-outburst, we estimate that the outburst began between 2005 April and 2007 March. We also model the pre-and post-outburst spectral energy distributions of the source, finding it to be in the late stages of accreting its envelope with a disk-to-star accretion rate that increased from ∼2 × 10 −6 M yr −1 to ∼10 −5 M yr −1 during the outburst. The post-outburst luminosity at the epoch of the FU Orionis-like near-IR spectra is 28 L , making V2775 Ori the least luminous documented FU Orionis outburster with a protostellar envelope. The existence of low-luminosity outbursts supports the notion that a range of episiodic accretion phenomena can partially explain the observed spread in protostellar luminosities.

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Results from HOPS: A multiwavelength census of Orion protostars

et al. 2013

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Surveys with the Spitzer and Herschel space observatories are now enabling the discovery and characterization of large samples of protostars in nearby molecular clouds, providing the observational basis for a detailed understanding of star formation in diverse environments. We are pursuing this goal with the Herschel Orion Protostar Survey (HOPS), which targets 328 Spitzer-identified protostars in the Orion molecular clouds, the largest star-forming region in the nearest 500 pc. The sample encompasses all phases of protostellar evolution and a wide range of formation environments, from dense clusters to relative isolation. With a grid of radiative transfer models, we fit the 1-870 μm spectral energy distributions (SEDs) of the protostars to estimate their envelope densities, cavity opening angles, inclinations, and total luminosities. After correcting the bolometric luminosities and temperatures of the sources for foreground extinction and inclination, we find a spread of several orders of magnitude in luminosity at all evolutionary states, a constant median luminosity over the more evolved stages, and a possible deficit of high-inclination, rapidly infalling envelopes among the Spitzer-identified sample. We have detected over 100 new sources in the Herschel images; some of them may fill this deficit. We also report results from modeling the pre-and post-outburst 1-870 μm SEDs of V2775 Ori (HOPS 223), a known FU Orionis outburster in the sample. It is the least luminous FU Ori star with a protostellar envelope.

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Predicted colors and flux densities of protostars in theHerschelPACS and SPIRE filters

Cited by 25 publications

References 13 publications

TheHerschelGould Belt Survey in Chamaeleon II

TheHerschelGould Belt Survey in Chamaeleon II

MULTIWAVELENGTH OBSERVATIONS OF V2775 Ori, AN OUTBURSTING PROTOSTAR IN L 1641: EXPLORING THE EDGE OF THE FU ORIONIS REGIME

Results from HOPS: A multiwavelength census of Orion protostars

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