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J/A+A/579/A80       Star-forming regions deuteration         (Gerner+, 2015)

Chemical evolution in the early phases of massive star formation. II. Deuteration. Gerner T., Shirley Y.L., Beuther H., Semenov D., Linz H., Albertsson T., Henning T. <Astron. Astrophys., 579, A80-80 (2015)> =2015A&A...579A..80G (SIMBAD/NED BibCode)
ADC_Keywords: Molecular clouds ; Spectroscopy Keywords: stars: formation - stars: early-type - ISM: molecules - evolution - astrochemistry Abstract: The chemical evolution in high-mass star-forming regions is still poorly constrained. Studying the evolution of deuterated molecules allows distinguishing between subsequent stages of high-mass star formation regions based on the strong temperature dependence of deuterium isotopic fractionation. We observed a sample of 59 sources including 19 infrared dark clouds, 20 high-mass protostellar objects, 11 hot molecular cores and 9 ultra-compact HII regions in the (3-2) transitions of the four deuterated molecules, DCN, DNC, DCO+, and N2D+ as well as their non-deuterated counterparts. The overall detection fraction of DCN, DNC, and DCO+ is high and exceeds 50% for most of the stages. N2D+ was only detected in a few infrared dark clouds and high-mass protostellar objects. This may be related to problems in the bandpass at the transition frequency and to low abundances in the more evolved, warmer stages. We find median D/H ratios of 0.02 for DCN, 0.005 for DNC, 0.0025 for DCO+, and 0.02 for N2D+. While the D/H ratios of DNC, DCO+, and N2D+ decrease with time, DCN/HCN peaks at the hot molecular core stage. We only found weak correlations of the D/H ratios for N2D+ with the luminosity of the central source and the FWHM of the line, and no correlation with the H2 column density. In combination with a previously observed set of 14 other molecules (Paper I), we fitted the calculated column densities with an elaborate 1D physico-chemical model with time-dependent D-chemistry including ortho- and para-H2 states. Good overall fits to the observed data were obtained with the model. This is one of the first times that observations and modeling were combined to derive chemically based best-fit models for the evolution of high-mass star formation including deuteration. Description: The sources were taken from Gerner et al. (2014, Cat. J/A+A/563/A97) and were initially selected from different source lists. The total sample contains 59 high-mass star-forming regions, consisting of 19 IRDCs and 20 HMPOs as well as 11 HMCs and 9 UCHIIs. The sources were selected from well-known source catalogs of the literature without specific selection criteria such as spherical symmetry. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file tablea1.dat 83 59 Source list showing the position, the distance, and the evolutionary stage of all high-mass star-forming regions tablea2.dat 98 59 Luminosity, H2, DCO+, DCN, DNC, and N2D+ column density and the corresponding error for each source tablea3.dat 75 59 HCO+, HCN, HNC, and N2H+ column density and corresponding error for each source
See also: J/A+A/563/A97 : IRAM 30m reduced spectra of 59 sources (Gerner+, 2014) Byte-by-byte Description of file: tablea1.dat
Bytes Format Units Label Explanations
1- 11 A11 --- Source Source name 13- 14 I2 h RAh Right ascension (J2000) 16- 17 I2 min RAm Right ascension (J2000) 19- 22 F4.1 s RAs Right ascension (J2000) 24 A1 --- DE- Declination sign (J2000) 25- 26 I2 deg DEd Declination (J2000) 28- 29 I2 arcmin DEm Declination (J2000) 31- 32 I2 arcsec DEs Declination (J2000) 34- 40 F7.3 deg GLON Galactic longitude 42- 48 F7.3 deg GLAT Galactic latitude 50- 54 F5.2 kpc Dist Distance (preferred one) 55 A1 --- n_Dist [deh] Note on Dist (1) 57- 61 F5.2 kpc Dist2 ? Alternative distance 62 A1 --- n_Dist2 [fij] Note on Dist2 (1) 64- 68 A5 --- Type Stage of source (4) 70 A1 --- 24um [yn- ] Embedded IRDC 24um point source ? (2) 72 A1 --- 70um [yn- ] Embedded IRDC 70um point source ? (2) 73 A1 --- n_70um [cg] Note on 70um (3) 76- 83 A8 --- Ref Sources of the dust continuum data (5)
Note (1): Distance notes as follows: d = For vlsr = 111.3km/s (preferred) or 97.6km/s (alternative) e = For vlsr = 100.2km/s (preferred) or 52.8km/s (alternative) f = For vlsr = 94.3km/s (preferred) or 98.4km/s (alternative) h = Ellsworth-Bowers et al. (2015ApJ...799...29E, Cat. J/ApJ/799/29) i = For the near (far) kinematic solution j = Parallactic (kinematic) distance Note (2): For the IRDCs we indicate whether or not they show embedded 24 or 70µm point sources with y(es) or n(o) (or "-" if there are no data available). Note (3): Note on 70um as follows: c = Very weak emission compared with the background located at the same position as 24um emission source. g = No embedded central point source found, a nearby extended source with emission inside the beam is detected. Note (4): the four stages are: IRDC = Infra-Red Cark Cloud stage (densities ≳105cm-3) HMPO = High-Mass protostellar Object (accreting protostar >8M☉) HMC = Hot Molecular Core (central source heats the surrounding environment) UCHII = Ultra-Compact HII region (UV radiation from protostar ionizes the surrounding gas) Note (5): Dust continuum data as follows: ATLASGAL = galactic plane survey ATLASGAL (870um; Schuller et al., 2009A&A...504..415S) Mambo = IRAM 30m observations with Mambo (1.2mm) SCUBA = SCUBA Legacy Catalog (850um; Di Francesco et al., 2008ApJS..175..277D, Cat. J/ApJS/175/277)
Byte-by-byte Description of file: tablea2.dat
Bytes Format Units Label Explanations
1- 11 A11 --- Source Source name 13- 17 F5.2 [Lsun] logL ? Luminosity 18 A1 --- r_logL [a-i] Luminosity reference (2) 20- 26 E7.2 cm-2 NH2 H2 column density (1) 28- 29 A2 --- l_DCO+ [≤ ] Limit flag on DCO+ 30- 36 E7.2 cm-2 DCO+ DCO+ column density 38- 44 E7.2 cm-2 e_DCO+ rms uncertainty on DCO+ measured integrated flux 46- 47 A2 --- l_DCN [≤ ] Limit flag on DCN 48- 54 E7.2 cm-2 DCN DCN column density 56- 62 E7.2 cm-2 e_DCN rms uncertainty on DCN measured integrated flux 64- 65 A2 --- l_DNC [≤ ] Limit flag on DNC 66- 72 E7.2 cm-2 DNC ?=- DNC column density 74- 80 E7.2 cm-2 e_DNC rms uncertainty on DNC measured integrated flux 82- 83 A2 --- l_N2D+ [≤ ] Limit flag on N2D+ 84- 90 E7.2 cm-2 N2D+ ?=- N2D+ column density 92- 98 E7.2 cm-2 e_N2D+ rms uncertainty on N2D+ measured integrated flux
Note (1): H2 column density is averaged over a 29"-beam and for all other molecules over a 30"-beam. Note (2): References as follows: a = Ragan et al. (2012A&A...547A..49R, Cat. J/A+A/547/A49) b = Beuther et al. (2012A&A...538A..11B, Cat. J/A+A/538/A11) c = Sridharan et al. (2002ApJ...566..931S) d = Linz et al. (2005A&A...429..903L) e = Churchwell et al. (1990A&AS...83..119C) f = Chen et al. (2006ApJ...639..975C) g = Campbell et al. (1995ApJ...454..831C) h = Beuther et al. (2004ApJ...616L..31B) i = Wood & Churchwell (1989ApJ...340..265W)
Byte-by-byte Description of file: tablea3.dat
Bytes Format Units Label Explanations
1- 11 A11 --- Source Source name 13- 19 E7.2 cm-2 HCO+ HCO+ column density 21- 27 E7.2 cm-2 e_HCO+ rms uncertainty on HCO+ measured integrated flux and the optical depth τ (1) 29- 35 E7.2 cm-2 HCN ?=- HCN column density 37- 43 E7.2 cm-2 e_HCN ?=- rms uncertainty on HCN measured integrated flux and the optical depth τ (1) 45- 51 E7.2 cm-2 HNC HNC column density 53- 59 E7.2 cm-2 e_HNC rms uncertainty on HNC measured integrated flux and the optical depth τ (1) 61- 67 E7.2 cm-2 N2H+ N2H+ column density 69- 75 E7.2 cm-2 e_N2H+ rms uncertainty on N2H+ measured integrated flux and the optical depth τ (1)
Note (1): The high uncertainties are in some cases due to high uncertainties in the determined optical depth.
References: Gerner et al., Paper I 2014A&A...563A..97G, Cat. J/A+A/563/A97
(End) Patricia Vannier [CDS] 06-Oct-2015
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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