J/ApJ/874/172 H2CO & H110α obs. toward Aquila (Komesh+, 2019)
H2CO and H110α observations toward the Aquila Molecular Cloud.
Komesh T., Esimbek J., Baan W., Zhou J., Li D., Wu G., He Y., Sailanbek S.,
Tang X., Manapbayeva A.
<Astrophys. J., 874, 172 (2019)>
=2019ApJ...874..172K 2019ApJ...874..172K
ADC_Keywords: Molecular clouds; Interstellar medium; Radio lines
Keywords: ISM: molecules ; stars: formation
Abstract:
The formaldehyde H2CO(110-111) absorption line and H110α
radio recombination line have been observed toward the Aquila
Molecular Cloud using the Nanshan 25m telescope operated by the
Xinjiang Astronomical Observatory CAS. These first observations of the
H2CO (110-111) absorption line determine the extent of the
molecular regions that are affected by the ongoing star formation in
the Aquila molecular complex and show some of the dynamic properties.
The distribution of the excitation temperature Tex for H2CO
identifies the two known star formation regions W40 and Serpens South
as well as a smaller new region Serpens 3. The intensity and velocity
distributions of H2CO and 13CO(1-0) do not agree well with each
other, which confirms that the H2CO absorption structure is mostly
determined by the excitation of the molecules resulting from the star
formation rather than by the availability of molecular material as
represented by the distribution. Some velocity-coherent linear
13CO(1-0) structures have been identified in velocity channel maps
of H2CO and it is found that the three star formation regions lie on
the intersect points of filaments. The H110α emission is found
only at the location of the W40 HII region and spectral profile
indicates a redshifted spherical outflow structure in the outskirts of
the HII region. Sensitive mapping of H2CO absorption of the Aquila
Complex has correctly identified the locations of star formation
activity in complex molecular clouds and the spectral profiles reveal
the dominant velocity components and may identify the presence of
outflows.
Description:
The H2CO (110-111) absorption line (λ=6cm,
v0=4829.6594MHz) and the H110α radio recombination line (RRL)
(v0=4874.1570MHz) have been observed in the Aquila Molecular Cloud
during 2015 February using the Nanshan 25m radio telescope of the
Xinjiang Astronomical Observatory of the Chinese Academy of Sciences.
Objects:
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RA (ICRS) DE Designation(s)
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18 30 03 -02 02 40 AMC = NAME Aquila Cloud
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 72 182 Parameters of the H2CO (110-111) absorption line
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See also:
J/A+A/551/A28 : H2CO and CO in 4 molecular clouds (Tang+, 2013)
J/A+A/584/A91 : Catalog of dense cores in Aquila from Herschel (Konyves+, 2015)
J/ApJS/219/21 : Deep NIR survey toward Aquila. I. MHOs (Zhang+, 2015)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 arcmin oRA [-30/40] Offset in RA (1)
5- 7 I3 arcmin oDE [-30/40] Offset in DE (1)
9- 15 F7.4 K.km/s Flux [-1.11/-0.06] Flux density
17- 20 F4.2 K.km/s e_Flux [0.01/0.05] Uncertainty in Flux
22- 26 F5.3 km/s Vel [5.3/8.7] Velocity
28- 31 F4.2 km/s e_Vel [0.03/0.6] Uncertainty in Velocity
33- 37 F5.3 km/s Width [1.3/9.41] Width
39- 42 F4.2 km/s e_Width [0.07/2] Uncertainty in Width
44- 49 F6.3 K TL [-0.33/-0.03] Absorption line antenna
temperature
51- 55 F5.3 K TC [0.004/3.33]? Continuum brightness
57- 61 F5.2 --- tau [-0.3/0.62] Optical depth
63- 67 F5.2 10+12/cm2 N(H2CO) [1.96/18.7] H2CO column density
69- 72 F4.2 K Tex [0.18/4.8] Excitation temperature
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Note (1): The central position is RA:18:30:03, DEC:-2:02:40 (Eq=J2000).
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 02-Sep-2020