J/ApJS/224/5 The Herschel Orion Protostar Survey (HOPS): SEDs (Furlan+, 2016)
The Herschel Orion Protostar Survey: spectral energy distributions and fits
using a grid of protostellar models.
Furlan E., Fischer W.J., Ali B., Stutz A.M., Stanke T., Tobin J.J.,
Megeath S.T., Osorio M., Hartmann L., Calvet N., Poteet C.A., Booker J.,
Manoj P., Watson D.M., Allen L.
<Astrophys. J. Suppl. Ser., 224, 5 (2016)>
=2016ApJS..224....5F 2016ApJS..224....5F (SIMBAD/NED BibCode)
ADC_Keywords: YSOs ; Energy distributions ; Photometry, infrared ;
Photometry, millimetric/submm ; Surveys
Keywords: circumstellar matter; infrared: stars; methods: data analysis
stars: formation; stars: protostars
Abstract:
We present key results from the Herschel Orion Protostar Survey
(HOPS): spectral energy distributions (SEDs) and model fits of 330
young stellar objects, predominantly protostars, in the Orion
molecular clouds. This is the largest sample of protostars studied in
a single, nearby star formation complex. With near-infrared photometry
from 2MASS, mid- and far-infrared data from Spitzer and Herschel, and
submillimeter photometry from APEX, our SEDs cover 1.2-870µm and
sample the peak of the protostellar envelope emission at ∼100µm.
Using mid-IR spectral indices and bolometric temperatures, we classify
our sample into 92 Class 0 protostars, 125 Class I protostars, 102
flat-spectrum sources, and 11 Class II pre-main-sequence stars. We
implement a simple protostellar model (including a disk in an
infalling envelope with outflow cavities) to generate a grid of 30400
model SEDs and use it to determine the best-fit model parameters for
each protostar. We argue that far-IR data are essential for accurate
constraints on protostellar envelope properties. We find that most
protostars, and in particular the flat-spectrum sources, are well fit.
The median envelope density and median inclination angle decrease from
Class 0 to Class I to flat-spectrum protostars, despite the broad
range in best-fit parameters in each of the three categories. We also
discuss degeneracies in our model parameters. Our results confirm that
the different protostellar classes generally correspond to an
evolutionary sequence with a decreasing envelope infall rate, but the
inclination angle also plays a role in the appearance, and thus
interpretation, of the SEDs.
Description:
To summarize, starting from a sample of 410 Herschel Orion Protostar
Survey (HOPS) targets (see section 2), but excluding likely
contaminants and objects not observed or detected by PACS, there are
330 remaining objects that have Spitzer and Herschel data and are
considered protostars (based on their Spitzer classification from
Megeath et al. 2012, J/AJ/144/192). They form the sample studied in
this work.
In order to construct SEDs for our sample of 330 YSOs, we combined our
own Herschel/PACS observations (see Proposal KPOTtmegeath2) with
data from the literature and existing catalogs (see section 3.1).
To extend the SEDs into the submillimeter, most of the YSOs were also
observed in the continuum at 350 and 870um with the Atacama Pathfinder
Experiment (APEX) telescope (Stutz et al. 2013, J/ApJ/767/36).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 117 330 Classification and best-fit model parameters for
the HOPS sample of YSOs
table2.dat 621 410 SED data (photometry and IRS spectra) for the
HOPS targets
table7.dat 53 41 YSOs in the HOPS sample with no PACS data
table8.dat 44 29 Likely extragalactic contaminants in the HOPS sample
table9.dat 24 6 Targets in the HOPS sample with uncertain nature
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See also:
VI/139 : Herschel Observation Log (Herschel Science Centre, 2013)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
J/ApJ/821/52 : NIR survey of Spitzer YSOs in Orion (Kounkel+, 2016)
J/ApJ/818/59 : IN-SYNC. IV. YSOs in Orion A (Da Rio+, 2016)
J/ApJ/817/167 : JCMT Gould Belt Survey: dense cores in Orion B (Kirk+, 2016)
J/A+A/566/A45 : Orion optical-depth and column-density maps (Lombardi+, 2014)
J/ApJ/769/149 : IR spectroscopy in Orion A: transitional disks (Kim+, 2013)
J/ApJ/768/99 : X-ray survey of YSOs in Orion A (Pillitteri+, 2013)
J/ApJ/767/36 : APEX observations of HOPS protostars (Stutz+, 2013)
J/AJ/145/94 : Luminosities of protostars from Spitzer (Dunham+, 2013)
J/ApJS/208/28 : Hα survey in the ONC (Szegedi-Elek+, 2013)
J/AJ/144/192 : Spitzer survey of Orion A and B. I. YSOs (Megeath+, 2012)
J/AJ/144/31 : Spitzer+2MASS photom. of protostar cand. (Kryukova+, 2012)
J/ApJ/733/50 : ONC MIR photometric monitoring (Morales-Calderon+, 2011)
J/ApJS/181/321 : Properties of Spitzer c2d dark clouds (Evans+, 2009)
J/ApJ/693/L81 : Extinction in star-forming regions (McClure, 2009)
J/ApJ/677/401 : Xray properties of protostars in ONC (Prisinzano+, 2008)
J/ApJS/179/249 : Low-luminosity embedded protostar population (Dunham+, 2008)
J/A+A/392/239 : IR survey of outflows in Orion A (Stanke+, 2002)
J/A+A/291/943 : Protostellar cores (Ossenkopf+, 1994)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- --- [HOPS-]
6- 8 I3 --- HOPS [1/409] Identifier of the HOPS target
11- 17 F7.4 deg RAdeg Right ascension in degrees (J2000)
20- 26 F7.4 deg DEdeg Declination in degrees (J2000)
29- 32 A4 --- Class SED class (0, I, II or "flat"=flat-spectrum)
35- 41 F7.2 Lsun Lbol [0.02/1478] Bolometric luminosity
43- 48 F6.1 K Tbol [23/1250] Bolometric temperature
51- 56 F6.3 --- n [-0.8/2.7]?=99.999 4.5-24 micron spectral index
59- 64 F6.2 Lsun Ltot [0.06/607] Best-fit total luminosity
67- 69 I3 AU Rdisk [5/500] Best-fit disk (=centrifugal) radius
72- 79 E8.2 g/cm3 rho1000 Best-fit reference density at 1000AU
82- 89 E8.2 Msun Menv [0/7.2] Best-fit envelope mass within 2500AU
92- 93 I2 deg theta [5/45] Best-fit cavity opening angle
96- 97 I2 deg Inc [18/87] Best-fit inclination angle
99-103 F5.1 mag Av [0/120.3] Best-fit foreground extinction
in the V-band
106-109 F4.2 --- Scf [0.5/2] Best-fit scaling factor;
for model fluxes
112-117 F6.3 --- R [0.2/15.1] Best-fit R value (1)
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Note (1): The tabulated properties for HOPS 223 are very unreliable, since its
SED is affected by extreme variability.
Figure 21 displays the histogram of R values of the best model fits
for the 330 objects in our HOPS sample that have Spitzer and Herschel
data (more than two data points at different wavelengths) and are not
contaminants (see Section 2). The median R value is 3.10, while the
mean value is 3.29. See section 6.4 for further explanations.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- --- [HOPS-]
6- 8 I3 --- HOPS [0/409] Identifier of the HOPS target
10 A1 --- f_HOPS [d] Flag on HOPS (1)
12- 20 E9.3 Jy FJ [0/0.32]?=0 2MASS J-band flux (2)
22- 30 E9.3 Jy e_FJ [0/0.007]?=0 Uncertainty in FJ
32 I1 --- f_FJ [1,3] Flag on FJ (3)
34- 42 E9.3 Jy FH [0/2.1]?=0 2MASS H-band flux (2)
44- 52 E9.3 Jy e_FH [0/0.06]?=0 Uncertainty in FH
54 I1 --- f_FH [1,3] Flag on FH (3)
56- 64 E9.3 Jy FKs [0/5.8]?=0 2MASS Ks-band flux (2)
66- 74 E9.3 Jy e_FKs [0/0.1]?=0 Uncertainty in FKs
76 I1 --- f_FKs [1,3] Flg on FKs (3)
78- 86 E9.3 Jy F3.6 [0/1.4]?=0 Spitzer/IRAC 3.6um band flux (2)
88- 96 E9.3 Jy e_F3.6 [0/0.07]?=0 Uncertainty in F3.6
98 I1 --- f_F3.6 [1/3] Flag on F3.6 (3)
100-108 E9.3 Jy F4.5 [0/3]?=0 Spitzer/IRAC 4.5 micron band flux (2)
110-118 E9.3 Jy e_F4.5 [0/0.2]?=0 Uncertainty in 4.5Flux
120 I1 --- f_F4.5 [1/3] Flag on 4.5Flux (3)
122-130 E9.3 Jy F5.8 [0/16.2]?=0 Spitzer/IRAC 5.8um band flux (2)
132-140 E9.3 Jy e_F5.8 [0/0.9]?=0 Uncertainty in 5.8Flux
142 I1 --- f_F5.8 [1/3] Flag on 5.8Flux (3)
144-152 E9.3 Jy F8.0 [0/6]?=0 Spitzer/IRAC 8.0 micron band flux (2)
154-162 E9.3 Jy e_F8.0 [0/0.3]?=0 Uncertainty in F8.0
164 I1 --- f_F8.0 [1/3] Flag on F8.0 (3)
166-174 E9.3 Jy F24 [0/85]?=0 Spitzer/MIPS 24 micron band flux (2)
176-184 E9.3 Jy e_F24 [0/17]?=0 Uncertainty in F24
186 I1 --- f_F24 [1/3] Flag on F24 (3)
188-196 E9.3 Jy F70 [0.008/1001]?=0 Herschel/PACS 70 micron flux
198-206 E9.3 Jy e_F70 [0.001/51]?=0 Uncertainty in F70
208 I1 --- f_F70 [0/3]? Flag on F70 (3)
210-218 E9.3 Jy F100 [0.06/1084]?=0 Herschel/PACS 100 micron flux
220-228 E9.3 Jy e_F100 [0.009/57]?=0 Uncertainty in F100
230 I1 --- f_F100 [0/3]? Flag on F100 (3)
232-240 E9.3 Jy F160 [0.03/1153]?=0 Herschel/PACS 160 micron flux
242-250 E9.3 Jy e_F160 [0.004/59]?=0 Uncertainty in F160
252 I1 --- f_F160 [0/3]? Flag on F160 (3)
254-262 E9.3 Jy F350 [0.1/62]?=0 APEX/SABOCA 350 micron flux
264-272 E9.3 Jy e_F350 [0.07/25]?=0 Uncertainty in F350
274 I1 --- f_F350 [0/2]? FLag on F350 (3)
276-284 E9.3 Jy F870 [0/9]?=0 APEX/LABOCA 870 micron flux
286-294 E9.3 Jy e_F870 [0/2]?=0 Uncertainty in F870
296 I1 --- f_F870 [0/2]? Flag on F870 (3)
298-306 E9.3 Jy F5.4 [0/4.3]?=0 Spitzer/IRS 5.4 micron flux
308-316 E9.3 Jy e_F5.4 [0/0.3]?=0 Uncertainty in F5.4
318-326 E9.3 Jy F6.45 [0/4.6]?=0 Spitzer/IRS 6.45 micron flux
328-336 E9.3 Jy e_F6.45 [0/0.06]?=0 Uncertainty in F6.45
338-346 E9.3 Jy F7.5 [0/4.9]?=0 Spitzer/IRS 7.5 micron flux
348-356 E9.3 Jy e_F7.5 [0/0.2]?=0 Uncertainty in F7.5
358-366 E9.3 Jy F8.1 [0/5.1]?=0 Spitzer/IRS 8.1 micron flux
368-376 E9.3 Jy e_F8.1 [0/0.08]?=0 Uncertainty in F8.1
378-386 E9.3 Jy F8.6 [0/5.1]?=0 Spitzer/IRS 8.6 micron flux
388-396 E9.3 Jy e_F8.6 [0/0.2]?=0 Uncertainty in F8.6
398-406 E9.3 Jy F9.2 [0/4.9]?=0 Spitzer/IRS 9.2 micron flux
408-416 E9.3 Jy e_F9.2 [0/0.2]?=0 Uncertainty in F9.2
418-426 E9.3 Jy F9.8 [0/4.9]?=0 Spitzer/IRS 9.8 micron flux
428-436 E9.3 Jy e_F9.8 [0/0.09]?=0 Uncertainty in F9.8
438-446 E9.3 Jy F10.5 [0/33.3]?=0 Spitzer/IRS 10.5 micron flux
448-456 E9.3 Jy e_F10.5 [0/0.2]?=0 Uncertainty in F10.5
458-466 E9.3 Jy F12.5 [0/41.2]?=0 Spitzer/IRS 12.5 micron flux
468-476 E9.3 Jy e_F12.5 [0/0.5]?=0 Uncertainty in F12.5
478-486 E9.3 Jy F14.0 [0/48]?=0 Spitzer/IRS 14.0 micron flux
488-496 E9.3 Jy e_F14.0 [0/1]?=0 Uncertainty in F14.0
498-506 E9.3 Jy F16.5 [0/57]?=0 Spitzer/IRS 16.5 micron flux
508-516 E9.3 Jy e_F16.5 [0/1.1]?=0 Uncertainty in F16.5
518-526 E9.3 Jy F19.0 [0/70]?=0 Spitzer/IRS 19.0 micron flux
528-536 E9.3 Jy e_F19.0 [0/2]?=0 Uncertainty in F19.0
538-546 E9.3 Jy F23.0 [0/89]?=0 Spitzer/IRS 23.0 micron flux
548-556 E9.3 Jy e_F23.0 [0/2]?=0 Uncertainty in F23.0
558-566 E9.3 Jy F27.0 [0/105]?=0 Spitzer/IRS 27.0 micron flux
568-576 E9.3 Jy e_F27.0 [0/4]?=0 Uncertainty in F27.0
578-586 E9.3 Jy F31.0 [0/116]?=0 Spitzer/IRS 31.0 micron flux
588-596 E9.3 Jy e_F31.0 [0/7]?=0 Uncertainty in F31.0
598-606 E9.3 Jy F35.0 [0/130]?=0 Spitzer/IRS 35.0 micron flux
608-616 E9.3 Jy e_F35.0 [0/10]?=0 Uncertainty in F35.0
618-621 F4.2 --- Scf [0/7] IRS scaling factor (4)
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Note (1): HOPS 109, 111, 212, and 362 were not modeled; they are duplicates of
HOPS 40, 60, 211, and 169, respectively (See section C.2.1).
Note (2): To convert the 2MASS magnitudes and the Spizter magnitudes from
Megeath et al. (2012, J/AJ/144/192) to fluxes, we used the
following zero points: 1594Jy for FJ, 1024Jy for FH,
666.7Jy for FKs, 280.9Jy for F3.6, 179.7Jy for F4.5,
115.0Jy for F5.8, 64.1Jy for F8.0, and 7.17Jy for F24.
Note (3): Flag as follows:
0 = not observed;
1 = measured;
2 = upper limit;
3 = not detected.
Note (4): This factor is the scaling factor that was applied to all IRS
fluxes in each spectrum to bring them in agreement with the IRAC
and MIPS fluxes.
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- --- [HOPS]
6- 8 I3 --- HOPS [0/360]? Identifier of the HOPS target
10- 16 F7.4 deg RAdeg Right ascension in decimal degrees (J2000)
18- 24 F7.4 deg DEdeg Declination in decimal degrees (J2000)
26- 29 A4 --- Class Type based on SED classification
(0, I, II or flat)
31- 36 F6.3 Lsun Lbol [0.006/15.4] Bolometric luminosity
38- 43 F6.1 K Tbol [29/1880] Bolometric temperature
45- 50 F6.3 --- n [-0.6/1.6]? 4.5-24um SED slope
52- 53 I2 --- Fl [-1/0] Herschel PACS flag (-1=not observed;
0=not detected by PACS at 70um)
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Byte-by-byte Description of file: table8.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- --- [HOPS]
6- 8 I3 --- HOPS [21/351] Identifier of the HOPS target
10- 16 F7.4 deg RAdeg Right ascension in decimal degrees (J2000)
18- 24 F7.4 deg DEdeg Declination in decimal degrees (J2000)
26- 30 F5.3 Lsun Lbol [0.007/3.4] Bolometric luminosity
32- 37 F6.1 K Tbol [84/1082] Bolometric temperature
39- 44 F6.3 --- n [-0.3/1.8]? 4.5-24um SED slope
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Byte-by-byte Description of file: table9.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [HOPS]
6- 8 I3 --- HOPS [349/381] Identifier of the HOPS target
10- 16 F7.4 deg RAdeg Right ascension in decimal degrees (J2000)
18- 24 F7.4 deg DEdeg Declination in decimal degrees (J2000)
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 24-Jun-2016