J/AJ/147/140 SED of 24 class I and class II FU Orionis stars (Gramajo+, 2014)
Spectral energy distribution analysis of Class I and Class II FU Orionis stars.
Gramajo L.V., Rodon J.A., Gomez M.
<Astron. J., 147, 140 (2014)>
=2014AJ....147..140G 2014AJ....147..140G
ADC_Keywords: Stars, variable ; Stars, pre-main sequence ; Energy distributions
Keywords: circumstellar matter - infrared: stars - stars: formation -
stars: pre-main sequence - stars: variables: T Tauri, Herbig Ae/Be
Abstract:
FU Orionis stars (FUors) are eruptive pre-main sequence objects
thought to represent quasi-periodic or recurring stages of enhanced
accretion during the low-mass star-forming process. We characterize
the sample of known and candidate FUors in a homogeneous and
consistent way, deriving stellar and circumstellar parameters for each
object. We emphasize the analysis in those parameters that are
supposed to vary during the FUor stage. We modeled the spectral energy
distributions of 24 of the 26 currently known FUors, using the
radiative transfer code of Whitney et al. We compare our models with
those obtained by Robitaille et al. for Taurus class II and I sources
in quiescence periods by calculating the cumulative distribution of
the different parameters. FUors have more massive disks: we find that
∼80% of the disks in FUors are more massive than any Taurus class II
and I sources in the sample. Median values for the disk mass accretion
rates are ∼10-7M☉/yr versus ∼10-5M☉/yr for standard
young stellar objects (YSOs) and FUors, respectively. While the
distributions of envelope mass accretion rates for class I FUors and
standard class I objects are similar, FUors, on average, have higher
envelope mass accretion rates than standard class II and class I
sources. Most FUors (∼70%) have envelope mass accretion rates above
10-7M☉/yr. In contrast, 60% of the classical YSO sample has an
accretion rate below this value. Our results support the current
scenario in which changes experimented by the circumstellar disk
explain the observed properties of these stars. However, the increase
in the disk mass accretion rate is smaller than theoretically
predicted, although in good agreement with previous determinations.
Description:
In this work we present the modeling of the spectral energy
distributions (SEDs) of a sample of 24 class II and class I FU Orionis
stars. These SEDs were constructed from fluxes obtained from the
literature (Table2), including Spitzer InfraRed Spectrograph (IRS)
infrared spectra in the 5-35µm range obtained in 2003 December and
2004 May for V1515 Cyg, BBW 76, FU Ori, V346 Nor and V1057 Cyg (Green
et al., 2006ApJ...648.1099G 2006ApJ...648.1099G), and in the 5-14µm range obtained
between 2003 December and 2004 March for RNO 1B, RNO 1C, L1551 IRS5,
and Par 21 (Quanz et al., 2007ApJ...668..359Q 2007ApJ...668..359Q). For Re 50 N IRS1, we
used an ISO short wavelength spectrometer (SWS) spectrum in the
5-15µm range obtained by Quanz et al. (2007ApJ...668..359Q 2007ApJ...668..359Q) in 2007
October.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
stars.dat 12 24 The sample of FU Orionis stars
table2.dat 35 675 Fluxes used to construct the SED of each source
refs.dat 79 93 References
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See also:
II/314 : UKIDSS-DR8 LAS, GCS and DXS Surveys (Lawrence+ 2012)
II/297 : AKARI/IRC mid-IR all-sky Survey (ISAS/JAXA, 2010)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
V/114 : MSX6C Infrared Point Source Catalog (Egan+ 2003)
Byte-by-byte Description of file: stars.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Name Name of the FU Orionis star
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Name Name of the FU Orionis star
14- 17 A4 --- n_Name Pre or post-outburst observation for V1647 Ori
19- 25 F7.2 um lambda [0.1/3410] Wavelength λ
27- 32 E6.2 Jy Flux Flux density (1)
34- 35 I2 --- r_Flux [1/93] Reference for Flux; in refs.dat file
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Note (1): We compiled all the fluxes available in the literature between
∼0.3µm and ∼3mm. Different flux values for the same source at the same
wavelength from the same authors implies different apertures.
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Ref [1/93] Reference identifier
4- 22 A19 --- BibCode Bibliographic code
24- 47 A24 --- Aut Author's name
49- 79 A31 --- Cat VizieR catalog
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Sylvain Guehenneux [CDS] 02-Oct-2014