J/A+A/686/A205 Ammonia maser emission in Galactic high-mass SFRs (Yan+, 2024)
Discovery of widespread non-metastable ammonia masers in the Milky Way.
Yan Y.T., Henkel C., Menten K.M., Wilson T.L., Wootten A., Gong Y.,
Wyrowski F., Yang W., Brunthaler A., Kraus A., Winkel B.
<Astron. Astrophys. 686, A205 (2024)>
=2024A&A...686A.205Y 2024A&A...686A.205Y (SIMBAD/NED BibCode)
ADC_Keywords: H II regions ; Star Forming Region ; Masers ; Radio lines
Keywords: masers - ISM: clouds - HII regions
Abstract:
We present the results of a search for ammonia maser emission in 119
Galactic high-mass star-forming regions (HMSFRs) known to host 22GHz
H2O maser emission. Our survey has led to the discovery
ofnon-metastable NH3 inversion line masers toward 14 of these sources.
This doubles the number of known non-metastable ammonia masers in our
Galaxy, including nine new very high-excitation (J, K)=(9,6) maser
sources. These maser lines, including NH3 (5,4), (6,4), (6,5), (7,6),
(8,6), (9,6), (9,8), (10,8), and (11,9), arise from energy levels of
342K, 513K, 465K, 606K, 834K, 1090K, 942K, 1226K, and 1449K
above the ground state. Additionally, we tentatively report a new
metastable NH3 (3,3) maser in G048.49 and an NH3 (7,7) maser in
G029.95. Our observations reveal that all of the newly detected NH3
maser lines exhibit either blueshifted or redshifted velocities with
respect to the source systemic velocities. Among the non-metastable
ammonia maser lines, larger velocity distributions, offset from the
source systemic velocities, are found in the ortho-NH3 (K=3n)
transitions than in the para-NH3 (K{diff}3n) ones.
Description:
We report the discovery of at least 14 and likely 15 new ammonia maser
sources in the Milky Way, based on our K-bmd line survey with the
100-meter Effelsberg telescope. Our total sample consists of 119
sources exhibiting 22GHz H2O maser emission
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea3.dat 46 119 Our sample of 119 observed sources
tablea4.dat 99 126 New ammonia masers
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Byte-by-byte Description of file: tablea3.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Source Source name (GLLL.ll+B.bb)
14- 15 I2 h RAh Right ascension (J2000)
17- 18 I2 min RAm Right ascension (J2000)
20- 23 F4.1 s RAs Right ascension (J2000)
25 A1 --- DE- Declination sign (J2000)
26- 27 I2 deg DEd Declination (J2000)
29- 30 I2 arcmin DEm Declination (J2000)
32- 33 I2 arcsec DEs Declination (J2000)
35- 40 F6.2 km/s VLSR LSR velocity
42- 46 F5.2 [cm-2] logN(NH3) NH3 column density
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Byte-by-byte Description of file: tablea4.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Source Source name (GLLL.lll+B.bb)
14- 19 A6 --- Trans Transition (J, K)
21- 29 F9.3 MHz nu Frequency
31- 40 A10 "date" Epoch Onservation date
41 A1 --- n_Epoch [a] a for average
43- 46 F4.2 km/s spacing Channel spacing
48- 51 F4.2 Jy Snu ?=- Flux density at nu
53- 57 F5.3 Jy rms ?=- rms
59- 62 F4.2 Jy.km/s IntSnudnu ?=- Integrated flux density
64- 67 F4.2 Jy.km/s e_IntSnudnu ? Integrated flux density error
69- 74 F6.2 km/s VLSR ?=- LSR velocity
76- 79 F4.2 km/s e_VLSR ? LSR velocity error
81- 84 F4.2 km/s DVl/2 ?=- Line width of ammonia maser line
86- 89 F4.2 km/s e_DVl/2 ? Line width of ammonia maser line error
91- 94 F4.2 km/s EW(11) ? Intrinsic line widths of ammonia
(J, K)=(1,1) thermal emission
96- 99 F4.2 km/s e_EW(11) ? Intrinsic line widths of ammonia
(J, K)=(1,1) thermal emission error
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 06-Aug-2024