Access to Astronomical Catalogues

← Click to display the menu
J/ApJ/844/138    Optical spectroscopy toward Orion B fields    (Kounkel+, 2017)

Kinematics of the optically visible YSOs toward the Orion B molecular cloud. Kounkel M., Hartmann L., Mateo M., Bailey III J.I. <Astrophys. J., 844, 138 (2017)> =2017ApJ...844..138K
ADC_Keywords: Spectra, optical ; YSOs ; Molecular clouds ; Interstellar medium ; Radial velocities ; Equivalent widths ; Effective temperatures Keywords: ISM: individual objects (Orion B); ISM: kinematics and dynamics; stars: pre-main sequence Abstract: We present results from high-resolution optical spectra toward 66 young stars in the Orion B molecular cloud to study their kinematics and other properties. Observations of the Hα and Li I 6707Å lines are used to check membership and accretion properties. While the stellar radial velocities of NGC 2068 and L1622 are in good agreement with that of the molecular gas, many of the stars in NGC 2024 show a considerable offset. This could be a signature of either the expansion of the cluster, the high degree of the ejection of the stars from the cluster through dynamical interaction, or the acceleration of the gas due to stellar feedback. Description: We observed a total of four fields toward the Orion B with Michigan/Magellan Fiber System (M2FS), a multi-object spectrograph on the Magellan Clay Telescope. These fields included regions toward NGC2023, 2024, 2068, and L1622 (Table 1). Due to their spatial proximity, we consider NGC 2023 and NGC 2024 together in the analysis presented in this paper. All regions were observed with the Hα and LiI filters, simultaneously spanning two orders, covering the spectral range of 6525-6750Å with a spectral resolution R∼20000 between 2014 Dec and 2017 Mar. A maximum of 128 sources can be observed in this configuration, with the field of view of 29' in diameter. NGC 2068 has also been re-observed a second time with the Hα and the LiI filters, as well as the MgI filter, which spans the spectral range of 5100-5210Å. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 61 6 Dates and configurations of the M2FS observations table2.dat 115 439 Sources that were surveyed for the presence of LiI
See also: VI/120 : High-resolution synthetic stellar library (Coelho+, 2005) J/A+A/337/403 : Low-mass stars evolutionary models (Baraffe+ 1998) J/A+A/442/1127 : Library of 2500-10500Å synthetic spectra (Munari+, 2005) J/ApJ/648/1090 : Radial velocities of NGC 2264 stars (Furesz+, 2006) J/ApJ/646/1215 : Low-mass stars and brown dwarfs in NGC 2024 (Levine+, 2006) J/ApJ/676/1109 : Velocities of stars in the ONC (Furesz+, 2008) J/AJ/135/966 : Circumstellar disk evolution in NGC 2068/71 (Flaherty+, 2008) J/A+A/504/461 : YSOs in L1630N and L1641 (Fang+, 2009) J/ApJ/697/1103 : Kinematics of Orion Nebula Cluster (Tobin+, 2009) J/AJ/144/192 : Spitzer survey of Orion A & B. I. YSO catalog (Megeath+, 2012) J/ApJ/787/109 : Age estimates for NGC 2024 and ONC stars (Getman+, 2014) J/AJ/149/119 : Radial velocities of stars in NGC 2264 (Tobin+, 2015) J/ApJ/808/108 : M2FS stellar spectroscopy of Reticulum 2 (Walker+, 2015) J/ApJ/818/59 : IN-SYNC. IV. YSOs in Orion A (Da Rio+, 2016) J/ApJ/821/8 : Spectroscopic binary pop. of ONC and NGC2264 (Kounkel+, 2016) J/ApJ/834/142 : Gould's Belt Dist. Survey (GOBELINS). II. OMC (Kounkel+, 2017) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 3 A3 --- Cat Catalog ID (NGC or "L" for LDN) 5- 8 I4 --- Field [1622/2068] Field identifier (as in table 2) 10- 20 A11 "Y/M/D" Date UT date of observation 22- 23 I2 h RAh Hour of right ascension (J2000) 25- 26 I2 min RAm Minute of right ascension (J2000) 28- 31 F4.1 s RAs Second of right ascension (J2000) 33 A1 --- DE- Sign of declination (J2000) 34- 35 I2 deg DEd Degree of declination (J2000) 37- 38 I2 arcmin DEm Arcminute of declination (J2000) 40- 41 I2 arcsec DEs Arcsecond of declination (J2000) 43 I1 --- N [3] Number of exposure time 44 A1 --- --- [x] 45- 48 I4 s Exp [720/1800] Exposure time (xN) 50- 61 A12 --- Filt Filter(s)
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 5 A5 --- Seq RV number (2533 to 2825 with 2734a,b and 2670a,b) 7- 8 I2 h RAh Hour of Right Ascension (J2000) 10- 11 I2 min RAm Minute of Right Ascension (J2000) 13- 17 F5.2 s RAs Second of Right Ascension (J2000) 19 A1 --- DE- Sign of the Declination (J2000) 20- 21 I2 deg DEd Degree of Declination (J2000) 23- 24 I2 arcmin DEm Arcminute of Declination (J2000) 26- 29 F4.1 arcsec DEs Arcsecond of Declination (J2000) 31- 36 F6.2 km/s RVel [-71/130]? Radial velocity 38- 41 F4.2 km/s e_RVel [0.2/8.2]? Uncertainty in RVel 43- 47 F5.2 --- R [2/33]? Tonry & Davis 1979AJ.....84.1511T Signal-to-Noise R value 49- 52 F4.2 0.1nm WLi [0.1/0.9]? Equivalent width of Li I 54- 59 F6.2 0.1nm WHa [-33/2.5]? Equivalent width of Hα (1) 61- 63 I3 km/s VHa [109/671]? Hα velocity 65- 80 A16 --- YSO YSO type (Class III: 50 occurrences; Class II: 48 occurrences) 81 A1 --- f_YSO [d] Flag on YSO (2) 83 A1 --- RR? Rapid rotator flag (3) 85- 88 I4 K Teff [3500/7000]? Effective temperature 90- 98 F9.1 d JD Julian Date of observation 100-110 A11 --- Order Order used for cross-correlation 112-115 I4 --- Field [1622/2068] Field identifier
Note (1): Negative values show that the line appeared in emission. Most lines were contaminated by the nebular emission lines; this emission has been masked. Note (2): d = Not observed with Spitzer, classified based on their Hα. Note (3): Whether or not the source was processed with the rapid rotator parameters during cross-correlation (see Paper I; Kounkel+, 2016, J/ApJ/821/8 for full discussion).
History: From electronic version of the journal References: Kounkel et al. Paper I. 2016ApJ...821....8K Cat. J/ApJ/821/8
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 07-Mar-2018
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

catalogue service

© UDS/CNRS

Contact