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J/AJ/154/163   WISE-selected candidate SFRs beyond the Outer Arm  (Izumi+, 2017)

Star formation activity beyond the Outer Arm. I. WISE-selected candidate star-forming regions. Izumi N., Kobayashi N., Yasui C., Saito M., Hamano S. <Astron. J., 154, 163 (2017)> =2017AJ....154..163I (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Molecular clouds ; Star Forming Region ; Photometry, infrared Keywords: Galaxy: formation - infrared: stars - ISM: clouds - stars: formation Abstract: The outer Galaxy beyond the Outer Arm provides a good opportunity to study star formation in an environment significantly different from that in the solar neighborhood. However, star-forming regions in the outer Galaxy have never been comprehensively studied or cataloged because of the difficulties in detecting them at such large distances. We studied 33 known young star-forming regions associated with 13 molecular clouds at RG≥13.5 kpc in the outer Galaxy with data from the Wide-field Infrared Survey Explorer (WISE) mid-infrared all-sky survey (Wright et al. 2010AJ....140.1868W; Jarrett et al. 2011ApJ...735..112J). From their color distribution, we developed a simple identification criterion of star-forming regions in the outer Galaxy with the WISE color. We applied the criterion to all the WISE sources in the molecular clouds in the outer Galaxy at RG≥13.5 kpc detected with the Five College Radio Astronomy Observatory (FCRAO) 12CO survey of the outer Galaxy (Heyer et al. 1998ApJS..115..241H), of which the survey region is 102.49°=<l=<141.54°, -3.03°=<b=<5.41°, and successfully identified 711 new candidate star-forming regions in 240 molecular clouds. The large number of samples enables us to perform the statistical study of star formation properties in the outer Galaxy for the first time. This study is crucial to investigate the fundamental star formation properties, including star formation rate, star formation efficiency, and initial mass function, in a primordial environment such as the early phase of the Galaxy formation. Description: In this paper, we use the WISE MIR all-sky survey data (Wright et al. 2010AJ....140.1868W; Jarrett et al. 2011ApJ...735..112J) and FCRAO 12CO survey data of the outer Galaxy (Heyer et al. 1998ApJS..115..241H). WISE mapped at least eight times over 99% of the sky in four MIR bands centered at 3.4, 4.6, 12, and 22 µm in the six-month survey in 2010 (Wright et al. 2010AJ....140.1868W). We used the AllWISE Source Catalog (http://wise2.ipac.caltech.edu/docs/release/allwise/) to obtain the WISE magnitudes and colors of the sample star-forming regions. The FCRAO 12CO survey of the outer Galaxy (Heyer et al. 1998) has achieved the best combination of large-area coverage and high sensitivity among all of the available CO surveys of the outer Galaxy. In this paper, we employed the molecular cloud catalog by Brunt et al. (2003, J/ApJS/144/47) to make use of the larger number of clouds compared with the original catalog by Heyer et al. (2001, J/ApJ/551/852). File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 68 13 Molecular clouds with associating sample star-forming regions in the FOG and EOG table2.dat 126 99 Sample and candidate star-forming regions and the WISE sources in the outer Galaxy table3.dat 50 15 Contamination rate for molecular clouds with associating sample star-forming regions table4.dat 75 252 Molecular clouds with associating new candidate star-forming regions table5.dat 103 792 New candidate star-forming regions
See also: II/328 : AllWISE Data Release (Cutri+ 2013) J/ApJ/551/852 : FCRAO CO survey of the outer Galaxy (Heyer+, 2001) J/A+A/399/1083 : Outer Galaxy IRAS sources and 12CO emission (Kerton+, 2003) J/ApJS/144/47 : Outer galaxy molecular cloud catalog (Brunt+, 2003) J/A+A/464/909 : JHK photometry near IRAS 06145+1455 (Brand+, 2007) J/ApJS/212/1 : The WISE catalog of Galactic HII regions (Anderson+, 2014) J/ApJS/224/7 : CO obs. of the outer arm in the 2nd quadrant (Du+, 2016) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 3 A3 --- Region [EOG FOG] Region (EOG=Extreme Outer Galaxy, FOG=Far Outer Galaxy) 5- 20 A16 --- Cloud Molecular cloud identifier 22- 28 F7.3 deg GLON [130.539/195.82] Galactic longitude 30- 35 F6.3 deg GLAT [-1/2.797] Galactic latitude 37- 43 F7.2 km/s VLSR [-102.4/34.01] Local standard of rest velocity of cloud 45- 48 F4.1 kpc Dist [6.3/16] Kinematic distance 50- 53 F4.1 kpc Rgal [13.5/22] Galactocentric radius 55 A1 --- l_Age [<] Limit flag on Age 56- 58 F3.1 Myr b_Age [0.5/1]? Minimum of cloud age range 60- 62 F3.1 Myr B_Age [1]? Maximum of cloud age range 64- 68 A5 --- Ref References (1)
Note (1): Reference as follows: 1 = Digel et al. (1994ApJ...422...92D); 2 = Izumi et al. (2014ApJ...795...66I); 3 = Kobayashi et al. (2008ApJ...683..178K); 4 = Yasui et al. (2008ApJ...675..443Y); 5 = Brand & Wouterloot (1994A&AS..103..503B); 6 = Brand & Wouterloot (2007, J/A+A/464/909); 7 = Heyer et al. (1998ApJS..115..241H); 8 = Snell et al. (2002ApJ...578..229S).
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 3 A3 --- Region [EOG FOG] Region (EOG=Extreme Outer Galaxy, FOG=Far Outer Galaxy) 5- 20 A16 --- Cloud Molecular cloud identifier 22- 32 A11 --- SFR Previous identification of the star-forming region (1) 34- 39 A6 --- Type SFR type (2) 41- 59 A19 --- WISE ALLWISE position based identifier 61- 67 F7.3 deg GLON [130.54/195.823] Galactic longitude of ALLWISE source 69- 74 F6.3 deg GLAT [-1.108/2.767] Galactic latitude of ALLWISE source 76- 81 F6.3 mag W1mag [9.211/17.11] ALLWISE W1 (3.35µm) band magnitude 83- 87 F5.3 mag e_W1mag [0.016/0.191] Uncertainty in W1mag 89- 94 F6.3 mag W2mag [7.435/15.844] ALLWISE W2 (4.6µm) band magnitude 96-100 F5.3 mag e_W2mag [0.014/0.153] Uncertainty in W2mag 102-107 F6.3 mag W3mag [3.379/11.362] ALLWISE W3 (11.6µm) band magnitude 109-113 F5.3 mag e_W3mag [0.005/0.212] Uncertainty in W3mag 115-120 F6.3 mag W4mag [-0.009/8.802] ALLWISE W4 (22.1µm) band magnitude 122-126 F5.3 mag e_W4mag [0.004/0.526]? Uncertainty in W4mag (G2)
Note (1): Star forming regions are defined as follows: Q = Star-forming region (cluster/stellar aggregates) unpublished yet but separately identified from our Subaru and QUIRC data (Izumi et al. 2017, in preparation); CAN = Candidate star-forming region newly identified with the WISE data (Wright et al. 2010AJ....140.1868W; Jarrett et al. 2011ApJ...735..112J); see Section 3.1. Other star-forming regions are literature ID from Kobayashi et al. (2008ApJ...683..178K), Yasui et al. (2008ApJ...675..443Y), Snell et al. (2002ApJ...578..229S) or Izumi et al. (2014ApJ...795...66I). Note (2): Star forming region type as follows: A = Aggregate; EC = Embedded cluster; EC+HII = Embedded cluster with HII region, Snell et al. (2002ApJ...578..229S).
Byte-by-byte Description of file: table3.dat
Bytes Format Units Label Explanations
1- 16 A16 --- Cloud Molecular cloud identifier 18- 22 A5 --- Source Survey data source (NRO, FCRAO) 24- 25 I2 --- NSFR [0/25]? Number of SFR and candidate SFR in the cloud 27- 29 I3 arcmin2 Area [18/130]? Cloud area 31- 36 E6.4 arcmin-2 dSFR [0.024/0.54]? Density of SFR and candidate SFR in the cloud 38- 40 I3 --- NCand [21/147]? Number of candidate SFR in the field 42- 47 E6.4 arcmin-2 dCand [0.0072/0.054]? Density of candidate SFR in in the field 49- 50 I2 % Cont [3/54]? Contamination rate
Byte-by-byte Description of file: table4.dat
Bytes Format Units Label Explanations
1- 9 A9 --- --- ([BKP2003] ) 10- 14 I5 --- [BKP2003] Cloud identification number ([BKP2003]NNNNN) (G1) 16- 22 F7.3 deg GLON [102.632/141.464] Galactic longitude (G1) 24- 29 F6.3 deg GLAT [-2.044/5.099] Galactic latitude (G1) 31- 37 F7.2 km/s VLSR [-107.35/-50.66] Local standard of rest velocity of cloud centroid (G1) 39- 43 F5.2 kpc Dist [5.8/21.5] Kinematic distance (1) 45- 48 F4.1 kpc Rgal [13.5/28.3] Galactocentric radius 50- 51 I2 --- NCand [1/24] Number of candidate(s) in the cloud 53- 58 F6.2 % Cont [1/231] Contamination rate 60- 75 A16 --- Note Note (2)
Note (1): Distances derived assuming that the rotation speed of the Sun and BKP clouds is 220 km/s and that the Galactocentric distance of the Sun is 8.5 kpc. Note (2): Notes include the name of the 12 molecular clouds, which were used as molecular clouds with associating sample star-forming regions (Table 3, Figures 2 and 5). CO peak of Digel Cloud 1a were not detected from FCRAO CO survey of the outer Galaxy.
Byte-by-byte Description of file: table5.dat
Bytes Format Units Label Explanations
1- 9 A9 --- --- ([BKP2003] ) 10- 14 I5 --- [BKP2003] Cloud identification number ([BKP2003]NNNNN) (G1) 16 A1 --- f_ID [m] Multiple clouds flag for source (1) 18- 36 A19 --- WISE ALLWISE position based identifier 38- 44 F7.3 deg GLON [102.59/141.479] Galactic longitude of ALLWISE source 46- 51 F6.3 deg GLAT [-2.04/5.14] Galactic latitude of ALLWISE source 53- 58 F6.3 mag W1mag [7.879/17.537] ALLWISE W1 (3.35µm) band magnitude 60- 64 F5.3 mag e_W1mag [0.014/0.213] Uncertainty in W1mag 66- 71 F6.3 mag W2mag [6.733/16.202] ALLWISE W2 (4.6µm) band magnitude 73- 77 F5.3 mag e_W2mag [0.014/0.195] Uncertainty in W2mag 79- 84 F6.3 mag W3mag [1.41/12.184] ALLWISE W3 (11.6µm) band magnitude 86- 90 F5.3 mag e_W3mag [0.005/0.219] Uncertainty in W3mag 92- 97 F6.3 mag W4mag [-2.147/9.441] ALLWISE W4 (22.1µm) band magnitude 99-103 F5.3 mag e_W4mag [0.002/0.542]? Uncertainty in W4mag (G2)
Note (1): More than one cloud at different velocities exist in the line of sight for 13 candidates marked with "m".
Global notes: Note (G1): Identifiers (Tables 4 and 5), positions, and VLSR (Table 4) taken from the cloud catalog of Brunt et al. (2003, J/ApJS/144/47). Note (G2): A null value indicates the profile-fit magnitude is a 95% confidence upper limit or the source is not measurable.
History: From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 17-Jul-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

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