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J/AJ/153/214   Star-forming potential in the Perseus complex   (Mercimek+, 2017)

An estimation of the star formation rate in the Perseus complex. Mercimek S., Myers P.C., Lee K.I., Sadavoy S.I. <Astron. J., 153, 214-214 (2017)> =2017AJ....153..214M (SIMBAD/NED BibCode)
ADC_Keywords: Molecular clouds ; YSOs ; Stars, masses ; Stars, diameters Keywords: ISM: individual objects: Perseus - stars: formation - stars: protostars Abstract: We present the results of our investigation of the star-forming potential in the Perseus star-forming complex. We build on previous starless core, protostellar core, and young stellar object (YSO) catalogs from Spitzer (3.6-70 µm), Herschel (70-500 µm), and SCUBA (850 µm) observations in the literature. We place the cores and YSOs within seven star-forming clumps based on column densities greater than 5x1021/cm2. We calculate the mean density and free-fall time for 69 starless cores as ∼5.55x10-19 g/cm3 and ∼0.1 Myr, respectively, and we estimate the star formation rate for the near future as ∼150 M/Myr. According to Bonnor-Ebert stability analysis, we find that majority of starless cores in Perseus are unstable. Broadly, these cores can collapse to form the next generation of stars. We found a relation between starless cores and YSOs, where the numbers of young protostars (Class 0 + Class I) are similar to the numbers of starless cores. This similarity, which shows a one-to-one relation, suggests that these starless cores may form the next generation of stars with approximately the same formation rate as the current generation, as identified by the Class 0 and Class I protostars. It follows that if such a relation between starless cores and any YSO stage exists, the SFR values of these two populations must be nearly constant. In brief, we propose that this one-to-one relation is an important factor in better understanding the star formation process within a cloud. Description: We used published catalogs of cores and YSOs at different wavelengths ranging from sub-millimeter (850 µm) to infrared (1.25 µm). We focus on seven clumps in Perseus, which Sadavoy et al. (2014ApJ...787L..18S) showed in their Figure 1. They defined these clumps and their boundaries using a fitted Herschel-derived column density map. The column density threshold of AV∼7 mag is proposed as a star formation threshold by Andre et al. (2010A&A...518L.102A), Lada et al. (2010ApJ...724..687L), and Evans et al. (2014ApJ...782..114E) and is equal to N(H2)∼5x1021/cm2 (see also, Kirk et al. 2006, J/ApJ/646/1009; Andre et al. 2010A&A...518L.102A). We considered a core or YSO to be associated with a clump if it is located within the AV=7 mag contour of that clump from Sadavoy et al. (2014ApJ...787L..18S). We define a "source" to be a starless core or a YSO. Objects: ---------------------------------------------------------- RA (ICRS) DE Designation(s) ---------------------------------------------------------- 03 35.0 +31 13 Perseus = NAME Perseus Cloud ---------------------------------------------------------- File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table4.dat 61 69 Starless Cores in Each Clump table5.dat 61 42 Protostellar Cores in Each Clump table6.dat 38 28 Class 0 in Each Clump table7.dat 69 57 Class I in Each Clump table8.dat 69 26 Class Flat in Each Clump table9.dat 69 102 Class II in Each Clump table10.dat 69 9 Class III in Each Clump
See also: J/A+A/440/151 : Observations at 850um in Perseus clusters (Hatchell+, 2005) J/ApJ/638/293 : 1.1mm sources in the Perseus Molecular Cloud (Enoch+, 2006) J/ApJ/646/1009 : Structures of dust in Perseus molecular cloud (Kirk+, 2006) J/A+A/468/1009 : Star formation in Perseus. II. (Hatchell+, 2007) J/ApJ/683/822 : Star formation in Ophiuchus and Perseus II. (Jorgensen+, 2008) J/ApJ/684/1240 : Prestellar cores in Perseus, Serpens and Ophiuchus (Enoch+, 2008) J/ApJ/696/298 : Dense cores in Perseus (Foster+, 2009) J/ApJS/181/321 : Properties of Spitzer c2d dark clouds (Evans+, 2009) J/MNRAS/402/603 : Properties of SCUBA cores in Perseus mol. cloud (Curtis+, 2010) J/AJ/150/40 : The Spitzer c2d survey of clouds. XII. Perseus (Young+, 2015) J/ApJ/818/73 : Study of protostars in the Perseus molecular cloud (Tobin+, 2016) Byte-by-byte Description of file: table[45].dat
Bytes Format Units Label Explanations
1- 8 A8 --- Clump Clump name 10- 11 I2 --- Field [1/26] Field identifier 13- 28 A16 --- Name Core name (JHHMMSS.s+DDMMSS) 30- 37 F8.4 deg RAdeg Right Ascension in decimal degrees (J2000) 39- 46 F8.4 deg DEdeg Declination in decimal degrees (J2000) 48- 53 F6.3 Msun Mass [0.051/24.529] Mass 55- 61 E7.2 pc Reff [0.0082/76] Effective radius
Byte-by-byte Description of file: table6.dat
Bytes Format Units Label Explanations
1- 8 A8 --- Clump Clump name 10- 11 I2 --- Field [1/12] Field identifier 13- 19 A7 --- Name Source name 21 I1 h RAh Hour of Right Ascension (J2000) 23- 24 I2 min RAm Minute of Right Ascension (J2000) 26- 29 F4.1 s RAs Second of Right Ascension (J2000) 30 A1 --- DE- Sign of the Declination (J2000) 31- 32 I2 deg DEd Degree of Declination (J2000) 34- 35 I2 arcmin DEm Arcminute of Declination (J2000) 37- 38 I2 arcsec DEs Arcsecond of Declination (J2000)
Byte-by-byte Description of file: table[789].dat table10.dat
Bytes Format Units Label Explanations
1- 8 A8 --- Clump Clump name 10- 11 I2 --- Field [1/53] Field identifier 13- 31 A19 --- Name Spitzer source name ( 33- 51 A19 --- Class Spitzer c2d (Evans et al. 2009, J/ApJS/181/321) classification (1) 53- 60 F8.5 deg RAdeg Right Ascension in decimal degrees (J2000) 62- 69 F8.5 deg DEdeg Declination in decimal degrees (J2000)
Note (1): Classification from Evans et al. (2009, J/ApJS/181/321) as follows: YSOc = Candidates for YSOs. Detections in all four IRAC bands and MIPS-1; see selection criteria in section 3.1; red = Flux densities at 24 µm that are at least 3 times the flux density from the nearest available IRAC band; PAH_em = Have colors indicative of a peak in the 8 µm band; star+dust = The SED is consistent with that of a stellar photosphere for wavelengths shorter than a particular band but an excess in that band of at least 3σ. This band was appended to make a full name such as "YSOc_star+dust(MP1)" where MP1 implies the first MIPS band, at 24 µm or "YSOc_star+dust(IR4)" where IR4 implies the fourth IRAC band, at 8.0 µm; rising = Lack photometry at enough wavelengths to be classified as YSOc, but were later added as YSOs based on other information. The available flux densities rise significantly to longer wavelengths.
History: From electronic version of the journal
(End) Tiphaine Pouvreau [CDS] 18-May-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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