J/ApJ/768/99         X-ray survey of YSOs in Orion A         (Pillitteri+, 2013)

An X-ray survey of the young stellar population of the Lynds 1641 and iota Orionis regions. Pillitteri I., Wolk S.J., Megeath S.T., Allen L., Bally J., Gagne M., Gutermuth R.A., Hartman L., Micela G., Myers P., Oliveira J.M., Sciortino S., Walter F., Rebull L., Stauffer J. <Astrophys. J., 768, 99 (2013)> =2013ApJ...768...99P 2013ApJ...768...99P
ADC_Keywords: X-ray sources ; YSOs ; Photometry, infrared Keywords: stars: formation; stars: individual (Ori A, L1641, Iota Ori, V380 Ori, V883 Ori) Abstract: We present an XMM-Newton survey of the part of the Orion A cloud south of the Orion Nebula. This survey includes the Lynds 1641 (L1641) dark cloud, a region of the Orion A cloud with very few massive stars and hence a relatively low ambient UV flux, and the region around the O9III star ι Orionis. In addition to proprietary data, we used archival XMM data of the Orion Nebula Cluster (ONC) to extend our analysis to a major fraction of the Orion A cloud. We have detected 1060 X-ray sources in L1641 and the ι Ori region. About 94% of the sources have Two Micron All Sky Survey and Spitzer counterparts, 204 and 23 being Class II and Class I or protostar objects, respectively. In addition, we have identified 489 X-ray sources as counterparts to Class III candidates, given they are bright in X-rays and appear as normal photospheres at mid-IR wavelengths. The remaining 205 X-ray sources are likely distant active galactic nuclei or other galactic sources not related to Orion A. We find that Class III candidates appear more concentrated in two main clusters in L1641. The first cluster of Class III stars is found toward the northern part of L1641, concentrated around ι Ori. The stars in this cluster are more evolved than those in the Orion Nebula. We estimate a distance of 300-320 pc for this cluster showing that it is in the foreground of the Orion A cloud. Another cluster rich in Class III stars is located in L1641 South and appears to be a slightly older cluster embedded in the Orion A cloud. Furthermore, other evolved Class III stars are found north of the ONC toward NGC 1977. Description: The Survey of Orion A with XMM-Newton and Spitzer (SOXS) survey is composed of seven specifically proposed ∼50ks XMM-Newton fields, south of the ONC, to which we added four archival fields in the same region. See table 1 for the log of observations. The analysis of the Spitzer data and the IR catalog are discussed in Megeath et al. (2012, J/AJ/144/192). We used the IR catalog of Megeath et al. of objects detected in the four Infrared Array Camera (IRAC) bands and MIPS [24] band. The PSF width of Spitzer IRAC is ∼1.6" and thus better than the XMM-Newton PSF, while the PSF width of MIPS [24] is slightly worse (d∼6"). The XMM-Newton fields are almost fully contained in the Spitzer sky coverage, with the exception of small portions of fields S2, S3, S8, and S9, where a total of 16 X-ray sources lie outside the field of view of Spitzer. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table1.dat 82 19 List of XMM-Newton observations table2.dat 84 1060 List of X-ray detected sources table3.dat 105 232 Best fit parameters 1σ errors obtained from the modeling of X-ray spectra table4.dat 78 1041 List of X-ray and IR matches (970 X-ray sources); from erratum published in 2013, ApJ, 768, 99 table5.dat 79 12 *List of candidates with MIPS [24] excesses and two additional Class III candidates -------------------------------------------------------------------------------- Note on table5.dat: Photometry from Megeath+, 2012, J/AJ/144/192; except for the two additional candidates. -------------------------------------------------------------------------------- See also: B/xmm : XMM-Newton Observation Log (XMM-Newton Science Operation Center, 2012) J/A+A/564/A29 : Optical and near-infrared photometry in Orion A (Bouy+, 2014) J/ApJS/208/28 : Hα survey in the ONC (Szegedi-Elek+, 2013) J/ApJS/207/5 : YSOs in LDN 1641 with Hectochelle spectra (Fang+, 2013) J/ApJ/764/114 : BVRI photometry of stars in Orion A (Hsu+, 2013) J/ApJ/752/59 : Low-mass population in L1641 (Hsu+, 2012) J/AJ/144/192 : Spitzer survey of Orion A and B. I. YSO cat. (Megeath+, 2012) J/AJ/144/101 : Multiwavelength data of IRAS 20050+2720 SFR (Guenther+, 2012) J/AJ/144/31 : Spitzer+2MASS phot. of protostar candidates (Kryukova+, 2012) J/ApJ/733/50 : MIR phot. monitoring of the ONC (Morales-Calderon+, 2011) J/AJ/140/266 : NGC 1333 X-ray luminous YSOs properties (Winston+, 2010) J/AJ/139/950 : JHKs photometry in ONC (Robberto+, 2010) J/ApJ/725/2485 : X-rays from the star-forming complex W40 (Kuhn+, 2010) J/A+A/504/461 : YSOs in L1630N and L1641 (Fang+, 2009) J/ApJ/693/L81 : Extinction in star-forming regions (McClure, 2009) J/ApJS/184/18 : Spitzer survey of young stellar clusters (Gutermuth+, 2009) J/ApJ/677/401 : Xray properties of protostars in ONC (Prisinzano+, 2008) J/AJ/135/693 : X-ray and IR sources in RCW 108 (Wolk+, 2008) J/ApJ/665/1194 : Dense cores in the Orion A cloud survey (Ikeda+, 2007) J/ApJ/646/297 : Spitzer obs. of pre-main-sequence stars (Rebull+, 2006) J/ApJS/160/319 : COUP: observations and source lists (Getman+, 2005) J/AJ/128/2316 : BVRIJHKs photometry in sigma Ori cluster (Sherry+, 2004) J/AJ/128/787 : Chandra Orion flanking fields data (Ramirez+, 2004) J/AJ/119/3026 : Circumstellar disk candidates in Orion (Rebull+, 2000) J/ApJ/525/466 : Young low-mass stars & brown dwarfs in IC 348 (Luhman+, 1999) J/A+A/337/403 : Low-mass stars evolutionary models (Baraffe+ 1998) Byte-by-byte Description of file: table1.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 3 A3 --- Field Field name (starting with "S" for southern or "N" for northern fields) 5- 14 I010 --- ObsId Observation ID number (1) 16- 17 I2 h RAh [5] Hour of Right Ascension (J2000) 19- 20 I2 min RAm [34/42] Minute of Right Ascension (J2000) 22- 26 F5.2 s RAs Second of Right Ascension (J2000) 28 A1 --- DE- [-] Sign of Declination (J2000) 29- 30 I2 deg DEd [4/8] Degree of Declination (J2000) 32- 33 I2 arcmin DEm Arcminute of Declination (J2000) 35- 38 F4.1 arcsec DEs Arcsecond of Declination (J2000) 40- 50 A11 "YYYY/MMM/DD" Date Observation date (UT) 52- 55 F4.1 ks Exp [4.6/60] Exposure time after GTI filtering 57- 62 A6 --- Filt EPIC filter used during exposure (Thick, Medium or Thin1) 64- 82 A19 --- Notes Notes (archive data - other field name) -------------------------------------------------------------------------------- Note (1): For ObsID 0212481101 only the PN exposure has been analyzed. -------------------------------------------------------------------------------- Byte-by-byte Description of file: table2.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 4 A4 --- --- [SOXS] 5- 8 I4 --- SOXS [1/1060] Source identifier 10- 11 I2 h RAh [5] Hour of Right Ascension (J2000) 13- 14 I2 min RAm [33/43] Minute of Right Ascension (J2000) 16- 19 F4.1 s RAs Second of Right Ascension (J2000) 21 A1 --- DE- [-] Sign of the Declination (J2000) 22- 23 I2 deg DEd [5/8] Degree of Declination (J2000) 25- 26 I2 arcmin DEm Arcminute of Declination (J2000) 28- 31 F4.1 arcsec DEs Arcsecond of Declination (J2000) 33- 37 F5.2 arcmin Off [0.5/17.5] Off-axis distance (1) 39- 44 I6 ct Ct Net total (MOS1+MOS2+PN) 0.3-8keV counts 46- 50 I5 ct e_Ct Uncertainty in Ct 52- 58 F7.2 ct/ks Rate Count (0.3-8 keV) rate scaled to MOS sensitivity 60- 66 F7.3 ct/ks e_Rate Uncertainty in Rate 68- 73 F6.2 ks Exp [1/171] Sum of exposure times from EPIC cameras 75- 84 I010 --- ObsId XMM observation identifier -------------------------------------------------------------------------------- Note (1): With respect to the aim point of the observation. -------------------------------------------------------------------------------- Byte-by-byte Description of file: table3.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 4 I4 --- SOXS [4/1055] Source identifier 6- 12 A7 --- Model Model descriptor 14- 17 F4.2 --- chi2 [0.2/4.5] Reduced χ2 of model 19- 21 I3 --- DoF Degrees of freedom 23- 28 F6.2 10+20/cm2 NH [0/525] The NH column absorption 30- 35 F6.2 10+20/cm2 e_NH ? Uncertainty in NH 37- 41 F5.2 keV kT1 [0.1/64] First component kT value 43- 51 F9.2 keV e_kT1 Uncertainty in kT1 53- 59 F7.2 10-5/cm5 Norm1 First component normalization 61- 71 F11.2 10-5/cm5 e_Norm1 ? Uncertainty in Norm1 73- 76 F4.2 keV kT2 [0.2/1.2]? Second component kT value 78- 81 F4.2 keV e_kT2 ? Uncertainty in kT2 83- 88 F6.2 10-5/cm5 Norm2 ? Second component normalization 90- 94 F5.2 10-5/cm5 e_Norm2 ? Uncertainty in Norm2 96- 98 F3.1 --- Z [0/1.2]? Global abundance 100-105 F6.2 10-17W/cm2 Flux [1/875] The 0.3-8 keV X-ray flux; in 10-14erg/s/cm2 -------------------------------------------------------------------------------- Byte-by-byte Description of file: table4.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 4 I4 --- SOXS [1/1060] Source identifier (1) 6- 12 F7.4 deg RAdeg Right Ascension in decimal degrees (J2000) 14- 20 F7.4 deg DEdeg Declination in decimal degrees (J2000) 22- 26 F5.2 mag Jmag [3.4/17.1]? 2MASS J band magnitude 28- 32 F5.2 mag Hmag ? 2MASS H band magnitude 34- 38 F5.2 mag Kmag [3.7/15.4]? 2MASS Ks band magnitude 40- 44 F5.2 mag [3.6] [6/18]? Spitzer/IRAC 3.6µm band magnitude 46- 50 F5.2 mag [4.5] ? Spitzer/IRAC 4.5µm band magnitude 52- 56 F5.2 mag [5.8] ? Spitzer/IRAC 5.8µm band magnitude 58- 62 F5.2 mag [8.0] [3/15]? Spitzer/IRAC 8.0µm band magnitude 64- 68 F5.2 mag [24] [-0.3/10.4]? Spitzer/MIPS 24µm band magnitude 70 A1 --- I [F/T] A class 0/I/flat-spectrum object flag 72 A1 --- II [F/T] Class II candidate status (false or true) 74 A1 --- III [F/T] Class III candidate status (false or true) 76- 78 F3.1 arcsec Rad [0.1/5] Match radius between X-ray & IR positions -------------------------------------------------------------------------------- Note (1): X-ray sources with more than a potential IR counterpart have multiple entries. -------------------------------------------------------------------------------- Byte-by-byte Description of file: table5.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 3 I3 --- ID [13/468] ID number (1) 5 A1 --- f_ID [c] additional class III candidates (2) 7- 15 F9.6 deg RAdeg IR right ascension in decimal degrees (J2000) 17- 26 F10.7 deg DEdeg IR declination in decimal degrees (J2000) 28- 32 F5.2 mag Jmag [10.4/16.3]? 2MASS J band magnitude 34- 38 F5.2 mag Hmag [9.9/13.5]? 2MASS H band magnitude 40- 44 F5.2 mag Ksmag [9.8/13]? 2MASS Ks band magnitude 46- 51 F6.3 mag [3.6] [9/15]? Spitzer/IRAC 3.6µm band magnitude 53- 57 F5.2 mag [4.5] [8.7/15]? Spitzer/IRAC 4.5µm band magnitude 59- 64 F6.3 mag [5.8] [8.3/12.4]? Spitzer/IRAC 5.8µm band magnitude 66- 70 F5.2 mag [8.0] [7.7/12.4]? Spitzer/IRAC 8.0µm band magnitude 72- 75 F4.2 mag [24] [4.6/9.2]? Spitzer/MIPS 24µm band magnitude 77- 79 A3 --- Notes Notes (3) -------------------------------------------------------------------------------- Note (1): List of Candidates with MIPS [24] excesses, indicating that these may have transitional disks. Note (2): c = two additional class III candidates that are IR objects with incomplete Spitzer photometry and a match with X-ray sources. Note (3): Note as follows: a = Strong, isolated detection. b = Off of the main cloud region. c = Faint, near airy ring. d = Faint, in nebulosity, near the edge of detection; may be elongated; could be a contamination. e = Double source. f = Faint, only detected in IRAC [3.6] and [4.5]. -------------------------------------------------------------------------------- History: From electronic version of the journal * 12-Jan-2015: Insert into VizieR * 06-Jul-2015: Table 4 replaced with the one in erratum (2013, ApJ, 773, 80) * 11-May-2023: in Table 3, lignes appears twice, corrected now
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 26-Nov-2014
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