J/A+A/602/A37 Millimeter RRL in ATLASGAL-selected massive clumps (Kim+, 2017)
ATLASGAL-selected massive clumps in the inner Galaxy.
IV. Millimeter hydrogen recombination lines from associated H II regions.
Kim W.-J., Wyrowski F., Urquhart J.S., Menten K.M., Csengeri T.
<Astron. Astrophys. 602, A37 (2017)>
=2017A&A...602A..37K 2017A&A...602A..37K (SIMBAD/NED BibCode)
ADC_Keywords: Molecular clouds ; H II regions ; Interstellar medium ;
Radio lines ; Millimetric/submm sources
Keywords: surveys - stars: massive - stars: formation - H II regions -
ISM: general
Abstract:
Observations of millimeter wavelength radio recombination lines
(mm-RRLs) are used to search for HII regions in an unbiased way that
is complementary to many of the more traditional methods previously
used (e.g., radio continuum, far-infrared colors, maser emission). The
mm-RRLs can be used to derive physical properties of HII regions and
to provide velocity information of ionized gas. We carried out
targeted mm-RRL observations (39≤ principal quantum number (n) ≤65
and Δn = 1, 2, 3, and 4, named Hnα, Hnβ, Hnγ,
and Hnδ) using the IRAM 30m and Mopra 22m telescopes. In total,
we observed 976 compact dust clumps selected from a catalog of ∼10000
sources identified by the APEX Telescope Large Area Survey of the
Galaxy (ATLASGAL). The sample was selected to ensure a representative
mix of star-forming and quiescent clumps such that a variety of
different evolutionary stages is represented. Approximately half of
the clumps are mid-infrared quiet while the other half are
mid-infrared bright. We detected Hnα mm-RRL emission toward 178
clumps; Hnβ, Hnγ, and Hnδ were also detected toward
65, 23, and 22 clumps, respectively. This is the largest sample of
mm-RRLs detections published to date. Comparing the positions of these
clumps with radio continuum surveys we identified compact radio
counterparts for 134 clumps, confirming their association with known
HII regions. The nature of the other 44 detections is unclear, but 8
detections are thought to be potentially new HII regions while the
mm-RRL emission from the others may be due to contamination from
nearby evolved HII regions.
Broad linewidths are seen toward nine clumps (linewidth>40km/s)
revealing significant turbulent motions within the ionized gas; in the
past, such wide linewidths were found toward very compact and dense
HII regions. We find that the systemic velocity of the associated
dense molecular gas, traced by H13CO+(1-0), is consistent with the
mm-RRL velocities and confirms them as embedded HII regions. We also
find that the linewidth of the H13CO+(1-0) emission is
significantly wider than those without mm-RRL detection, indicating a
physical connection between the embedded H II region and their natal
environments. We also find a correlation between the integrated fluxes
of the mm-RRLs and the 6cm continuum flux densities of their radio
counterparts (the correlation coefficient, ρ, is 0.70). By
calculating the electron densities we find that the mm-RRL emission is
associated with HII regions with ne<105cm3 and HII region
diameter >0.03pc. We detected mm-RRLs toward 178 clumps and identified
eight new HII region candidates. The broad mm-RRL from nine clumps may
indicate that they arise in very young hyper-compact HII regions. The
mm-RRLs trace the radio continuum sources detected by high-resolution
observations and their line parameters show associations with the
embedded radio sources and their parental molecular clumps.
Description:
Measured parameters of hydrogen recombination lines toward 178 dust
clumps and more information of the 178 clumps are presented.
Parameters of radio continuum emission and mid-IR emission that are
associated with dust clumps with mm-RRL detection are also presented.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 108 178 Detail information of dust clumps that have
recombination line detections
table2_1.dat 117 178 Line parameters of hydrogen alpha RRLs
table2_2.dat 128 65 Line parameters of hydrogen beta RRLs
table2_3.dat 121 23 Line parameters of hydrogen gamma RRLs
table2_4.dat 131 22 Line parameters of hydrogen delta RRLs
table6.dat 52 90 Properties of radio continuum and mid-IR
emission toward dust clumps with mm-RRLs
img/* . 501 Individual radio continuum emission and mid-IR
emission images
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See also:
J/A+A/549/A45 : ATLASGAL. Compact Source Catalog: 330<l<21 (Contreras+, 2013)
J/MNRAS/435/400 : ATLASGAL. Properties of compact HII regions (Urquhart+, 2013)
J/A+A/568/A41 : ATLASGAL. Compact Source Catalog: 280<l<60 (Urquhart+, 2014)
J/A+A/586/A149 : SiO in ATLASGAL-selected massive clumps (Csengeri+, 2016)
J/A+A/599/A139 : ATLASGAL massive clumps dust characterization (Koenig+, 2017)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq ATLASGAL clump number
5- 22 A18 --- Name ATLASGAL clump name
24- 25 I2 h RAh Right Ascension J2000 (hours)
27- 28 I2 min RAm Right Ascension J2000 (minutes)
30- 33 F4.1 s RAs Right Ascension J2000 (seconds)
35 A1 --- DE- Declination J2000 (sign)
36- 37 I2 deg DEd Declination J2000 (degrees)
39- 40 I2 arcmin DEm Declination J2000 (minutes)
42- 43 I2 arcsec DEs Declination J2000 (seconds)
45- 48 F4.1 kpc Dist ? Heliocentric distance
50- 53 F4.2 [Msun] logM ? Log of the clump mass
55- 58 F4.2 [Lsun] logLbol ? Log of bolometric luminosity
60- 63 I4 km/s RRLVlsr LSR velocity of recombination line
65- 68 I4 km/s sysVlsr LSR systemic velocity of clumps
70- 78 A9 --- mid-IR Association with mid-IR emission
80 A1 --- Radio [YCN] Association with radio continuum
emission (1)
82-108 A27 --- Comm Comments about other informations
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Note (1): Flag as follows:
Y = radio continuum source is found within a radius of 18"
N = no radio continuum source found within a radius of 18"
C = possible contamination from nearby extended radio sources that are
located within a radius of 2'
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Byte-by-byte Description of file: table2_1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq ATLASGAL clump number
5- 22 A18 --- Name ATLASGAL clump name (AGALlll.lll+bb.bbb)
24- 28 F5.2 K.km/s Tint(Hna) Hna RRL integrated intensity on Ta* scale
30- 33 F4.2 K.km/s e_Tint(Hna) rms uncertainty on Tint(Hna)
35- 41 F7.2 km/s v(Hna) LSR velocity of Hna RRL
43- 46 F4.2 km/s e_v(Hna) rms uncertainty on v(Hna)
48- 52 F5.2 km/s dv(Hna) Hna linewidth
54- 58 F5.2 km/s e_dv(Hna) rms uncertainty on dv(Hna)
60- 63 F4.2 K Tpeak(Hna) Hna RRL peak intensity on Ta* scale
65- 69 F5.3 K rms rms noise per channel
71- 75 F5.2 K.km/s Tint(H39a) ? H39a RRL integrated intensity on Ta* scale
77- 81 F5.2 km/s dv(H39a) ? H39a linewidth
83- 87 F5.2 K.km/s Tint(H40a) ? H40a RRL integrated intensity on Ta* scale
89- 93 F5.2 km/s dv(H40a) ? H40a linewidth
95- 99 F5.2 K.km/s Tint(H41a) ? H41a RRL integrated intensity on Ta* scale
101-105 F5.2 km/s dv(H41a) ? H41a linewidth
107-111 F5.2 K.km/s Tint(H42a) ? H42a RRL integrated intensity on Ta* scale
113-117 F5.2 km/s dv(H42a) ? H42a linewidth
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Byte-by-byte Description of file: table2_2.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq ATLASGAL clump number
5- 22 A18 --- Name ATLASGAL clump name
24- 28 F5.2 K.km/s Tint(Hnb) Hnb RRL integrated intensity on Ta* scale
30- 33 F4.2 K.km/s e_Tint(Hnb) rms uncertainty on Tint(Hnb)
35- 40 F6.2 km/s v(Hnb) LSR velocity of Hnb RRL
42- 45 F4.2 km/s e_v(Hnb) rms uncertainty on v(Hnb)
47- 51 F5.2 km/s dv(Hnb) Hnb linewidth
53- 57 F5.2 km/s e_dv(Hnb) rms uncertainty on dv(Hnb)
59- 62 F4.2 K Tpeak(Hnb) Hnb RRL peak intensity on Ta* scale
64- 68 F5.3 K rms rms noise per channel
70- 74 F5.2 K.km/s Tint(H48b) ? H48b RRL integrated intensity on Ta* scale
76- 80 F5.2 km/s dv(H48b) ? H48b linewidth
82- 86 F5.2 K.km/s Tint(H49b) ? H49b RRL integrated intensity on Ta* scale
88- 92 F5.2 km/s dv(H49b) ? H49b linewidth
94- 98 F5.2 K.km/s Tint(H50b) ? H50b RRL integrated intensity on Ta* scale
100-104 F5.2 km/s dv(H50b) ? H50b linewidth
106-110 F5.2 K.km/s Tint(H51b) ? H51b RRL integrated intensity on Ta* scale
112-116 F5.2 km/s dv(H51b) ? H51b linewidth
118-122 F5.2 K.km/s Tint(H52b) ? H52b rRL integrated intensity on Ta* scale
124-128 F5.2 km/s dv(H52b) ? H52b linewidth
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Byte-by-byte Description of file: table2_3.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq ATLASGAL clump number
5- 22 A18 --- Name ATLASGAL clump name
24- 27 F4.2 K.km/s Tint(Hng) Hng RRL integrated intensity on Ta* scale
29- 32 F4.2 K.km/s e_Tint(Hng) rms uncertainty on Tint(Hng)
34- 38 F5.2 km/s v(Hng) LSR velocity of Hng RRL
40- 43 F4.2 km/s e_v(Hng) rms uncertainty on v(Hng)
45- 49 F5.2 km/s dv(Hng) Hng linewidth
51- 54 F4.2 km/s e_dv(Hng) rms uncertainty on dv(Hng)
56- 59 F4.2 K Tpeak(Hng) Hng RRL peak intensity on Ta* scale
61- 65 F5.3 K rms rms noise per channel
67- 70 F4.2 K.km/s Tint(H55g) ? H55g RRL integrated intensity on Ta* scale
72- 76 F5.2 km/s dv(H55g) ? H55g linewidth
78- 82 F5.2 K.km/s Tint(H56g) ? H56g RRL integrated intensity on Ta* scale
84- 88 F5.2 km/s dv(H56g) ? H56g linewidth
90- 93 F4.2 K.km/s Tint(H57g) ? H57g RRL integrated intensity on Ta* scale
95- 99 F5.2 km/s dv(H57g) ? H57g linewidth
101-104 F4.2 K.km/s Tint(H58g) ? H58g RRL integrated intensity on Ta* scale
106-110 F5.2 km/s dv(H58g) ? H58g linewidth
112-115 F4.2 K.km/s Tint(H60g) ? H60g RRL integrated intensity on Ta* scale
117-121 F5.2 km/s dv(H60g) ? H60g linewidth
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Byte-by-byte Description of file: table2_4.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq ATLASGAL clump number
5- 22 A18 --- Name ATLASGAL clump name
24- 27 F4.2 K.km/s Tint(Hnd) Hnd RRL integrated intensity on Ta* scale
29- 32 F4.2 K.km/s e_Tint(Hnd) rms uncertainty on Tint(Hnd)
34- 38 F5.2 km/s v(Hnd) LSR velocity of Hnd RRL
40- 43 F4.2 km/s e_v(Hnd) rms uncertainty on v(Hnd)
45- 49 F5.2 km/s dv(Hnd) Hnd linewidth
51- 54 F4.2 km/s e_dv(Hnd) rms uncertainty on dv(Hnd)
56- 59 F4.2 K Tpeak(Hnd) Hnd RRL peak intensity on Ta* scale
61- 65 F5.3 K rms rms noise per channel
67- 70 F4.2 K.km/s Tint(H60d) ? H60d RRL integrated intensity on Ta* scale
72- 76 F5.2 km/s dv(H60d) ? H60d linewidth
78- 81 F4.2 K.km/s Tint(H61d) ? H61d RRL integrated intensity on Ta* scale
83- 87 F5.2 km/s dv(H61d) ? H61d linewidth
89- 92 F4.2 K.km/s Tint(H62d) ? H62d RRL integrated intensity on Ta* scale
94- 98 F5.2 km/s dv(H62d) ? H62d linewidth
100-103 F4.2 K.km/s Tint(H63d) ? H63d RRL integrated intensity on Ta* scale
105-109 F5.2 km/s dv(H63d) ? H63d linewidth
111-114 F4.2 K.km/s Tint(H64d) ? H64d RRL integrated intensity on Ta* scale
116-120 F5.2 km/s dv(H64d) ? H64d linewidth
122-125 F4.2 K.km/s Tint(H65d) ? H65d RRL integrated intensity on Ta* scale
127-131 F5.2 km/s dv(H65d) ? H65d linewidth
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq ATLASGAL clump number
5- 22 A18 --- Name ATLASGAL clump name
24- 28 F5.1 Jy/beam Fpeak Radio continuum peak flux at 5GHz
30- 36 F7.1 Jy Fint Radio continuum integrated flux at 5GHz
38- 41 F4.1 arcsec Diam Radio continuum angular diameter
43- 47 F5.1 Jy F22 ? 22um emission flux
49- 52 F4.1 kpc Dist ? Heliocentric distance
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Acknowledgements:
Won-Ju Kim, wjkim(at)mpifr-bonn.mpg.de
References:
Urquhart et al., Paper I 2013MNRAS.435..400U 2013MNRAS.435..400U, Cat. J/MNRAS/435/400
Csengeri et al., Paper II 2016A&A...586A.149C 2016A&A...586A.149C, Cat. J/A+A/586/A149
Konig et al., Paper III 2017A&A...599A.139K 2017A&A...599A.139K, Cat. J/A+A/599/A139
(End) Patricia Vannier [CDS] 06-Apr-2017