J/MNRAS/526/2278 TEMPO. Fragmentation and emission properties (Avison+, 2023)
Tracing Evolution in Massive Protostellar Objects.
I. Fragmentation and emission properties of massive star-forming clumps in a
luminosity limited ALMA sample.
Avison A., Fuller G.A., Asabre Frimpong N., Etoka S., Hoare M., Jones B.M.,
Peretto N., Traficante A., van der Tak F., Pineda J.E., Beltran M.,
Wyrowski F., Thompson M., Lumsden S., Nagy Z., Hill T., Viti S.,
Fontani F., Schilke P.
<Mon. Not. R. Astron. Soc. 526, 2278-2300 (2023)>
=2023MNRAS.526.2278A 2023MNRAS.526.2278A (SIMBAD/NED BibCode)
ADC_Keywords: Associations, stellar ; Millimetric/submm sources ;
Morphology
Keywords: techniques: interferometric - stars: formation - stars: protostars -
ISM: clouds - submillimetre: ISM - submillimetre: stars
Abstract:
The role of massive (≥8M☉) stars in defining the energy budget
and chemical enrichment of the interstellar medium in their host
galaxy is significant. In this first paper from the Tracing Evolution
in Massive Protostellar Objects (TEMPO) project we introduce a
colour-luminosity selected (L*∼3x103 to 1x105L☉) sample of
38 massive star forming regions observed with ALMA at 1.3mm and
explore the fragmentation, clustering and flux density properties of
the sample. The TEMPO sample fields are each found to contain multiple
fragments (between 2-15 per field). The flux density budget is split
evenly (53%-47%) between fields where emission is dominated by a
single high flux density fragment and those in which the combined flux
density of fainter objects dominates. The fragmentation scales
observed in most fields are not comparable with the thermal Jeans
length, λJ, being larger in the majority of cases,
suggestive of some non-thermal mechanism. A tentative evolutionary
trend is seen between luminosity of the clump and the "spectral line
richness" of the TEMPO fields; with 6.7GHz maser associated fields
found to be lower luminosity and more line rich. This work also
describes a method of line-free continuum channel selection within
ALMA data and a generalised approach used to distinguishing sources
which are potentially star-forming from those which are not, utilising
interferometric visibility properties.
Description:
The TEMPO survey conducted a high resolution (0.8"), high sensitivity
(mean rms-noise ∼0.26mJy equivalent to ∼1.0-2.5M☉ for T=30/15K
respectively) ALMA survey of 38 colour-luminosity selected high-mass
star forming regions. The continuum emission from fragments within the
survey sample fields has been imaged and the clustering,
fragmentation, and distribution of emission has been assessed.
Additionally we have undertaken analysis to gauge whether the observed
sources are matter over-densities or centrally condensed (and
therefore likely currently star-forming).
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 120 38 Selection criteria properties of fields in
the sample
table4.dat 90 287 Sources detected in the TEMPO sample
--------------------------------------------------------------------------------
See also:
VIII/96 : 6-GHz methanol multibeam maser catalogue
(Caswell+, 2010-12)
J/ApJS/208/11 : The Red MSX Source Survey: massive protostars
(Lumsden+, 2013)
J/MNRAS/451/3089 : Young clumps embedded in IRDC (Traficante+, 2015)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 21 A21 --- Field Field name
23- 24 I2 h RAh Right Ascension (J2000)
26- 27 I2 min RAm Right Ascension (J2000)
29- 34 F6.3 s RAs Right Ascension (J2000)
35 A1 --- DE- Declination sign (J2000)
36- 37 I2 deg DEd Declination (J2000)
39- 40 I2 arcmin DEm Declination (J2000)
42- 47 F6.3 arcsec DEs Declination (J2000)
49- 52 F4.1 10+4Lsun L* Luminosity (1)
54- 59 F6.2 --- S70um/S22um ?=- 70um/22um flux ratio
60 A1 --- n_S70um/S22um [+] + for non-detection at 22um
62- 65 F4.2 kpc D Distance (1)
67 A1 --- Maser? [Y/N] CH3OH maser ? (2)
69- 72 F4.2 mJy rms rms noise
74- 77 F4.1 --- %-ageBW Percentage of the total observed bandwidth
(7.5GHz) which was used in imaging once
spectral line emission was removed
(see Sect. 2.3).
79- 82 F4.1 --- N [2/15] Number of sources detected in
each field
84- 87 F4.2 pc Rcl Distance from the arithmetic average source
position to the most distant source in
the cluster
89- 92 F4.2 pc FOV Field of view at the field distance
94- 97 F4.2 pc Xmean Mean edge length of the minimum spanning
tree of sources in each field
99-102 F4.2 pc lambdaJ Thermal Jeans length at Tclump
104-110 F7.1 Msun Mclump Clump mass (3)
112-115 F4.2 pc Rclump Clump radius (3)
117-120 F4.1 K Tclump Clump temperature (3)
--------------------------------------------------------------------------------
Note (1): taken from Lumsden et al. (2013ApJS..208...11L 2013ApJS..208...11L, Cat. J/ApJS/208/11,
and online material from the RMS survey) for RMS sources and Traficante et al.
(2015MNRAS.451.3089T 2015MNRAS.451.3089T, Cat. J/MNRAS/451/3089) for SDC sources.
Note (2): A 6.7GHz CH3OH maser is deemed associated with the field if it lays
within one ALMA primary beam (at our observing frequency) of the field
pointing position, maser positions were taken from the MMB survey catalogues
(Breen et al., 2015MNRAS.450.4109B 2015MNRAS.450.4109B; Green et al., 2012MNRAS.420.3108G 2012MNRAS.420.3108G,
Cat. VIII/96; Caswell et al., 2011MNRAS.417.1964C 2011MNRAS.417.1964C, Cat. VIII/96;
2010MNRAS.404.1029C 2010MNRAS.404.1029C, Cat. VIII/96).
Note (3): as derived by Elia et al. (2021MNRAS.504.2742E 2021MNRAS.504.2742E) from Herschel data.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 21 A21 --- Field Field name as specified in Table 1
23- 24 I2 --- SNum [0/14] Source number of the TEMPO fragment field
26- 27 I2 h RAh Right Ascension (J2000)
29- 30 I2 min RAm Right Ascension (J2000)
32- 37 F6.3 s RAs Right Ascension (J2000)
39 A1 --- DE- Declination sign (J2000)
40- 41 I2 deg DEd Declination (J2000)
43- 44 I2 arcmin DEm Declination (J2000)
46- 51 F6.3 arcsec DEs Declination (J2000)
53- 58 F6.3 arcsec aMaj Fitted Major axis
60- 65 F6.3 arcsec bMin Fitted Minor axis
67- 73 F7.2 deg PA [] Position Angle
75- 82 F8.3 mJy SCont Measured source continuum flux density
84 I1 --- ASC [0/3] Fragment ASC score as defined in Appdix C
86 I1 --- Bright [0/1] Brightest fragment in field (1)
88 I1 --- CentAr [0/1] Most central fragment in field
(arithmetic mean) (1)
90 I1 --- CentWe [0/1] Most central fragment in field
(weighted mean) (1)
--------------------------------------------------------------------------------
Note (1): Code as follows:
1 = True
0 = False
--------------------------------------------------------------------------------
Acknowledgements:
Adam Avison, adam.avison(at)skao.int
(End) Patricia Vannier [CDS] 26-Sep-2023