2018MNRAS.476.2446A


C.D.S. - SIMBAD4 rel 1.7 - 2020.02.17CET23:01:31

2018MNRAS.476.2446A - Mon. Not. R. Astron. Soc., 476, 2446-2456 (2018/May-2)

Study of diffuse H II regions potentially forming part of the gas streams around Sgr A*.

ARMIJOS-ABENDANO J., LOPEZ E., MARTIN-PINTADO J., BAEZ-RUBIO A., ARAVENA M., REQUENA-TORRES M.A., MARTIN S., LLERENA M., ALDAS F., LOGAN C. and RODRIGUEZ-FRANCO A.

Abstract (from CDS):

We present a study of diffuse extended ionized gas towards three clouds located in the Galactic Centre (GC). One line of sight (LOS) is towards the 20 km s–1 cloud (LOS-0.11) in the Sgr A region, another LOS is towards the 50 km s–1 cloud (LOS-0.02), also in Sgr A, while the third is towards the Sgr B2 cloud (LOS+0.693). The emission from the ionized gas is detected from Hnα and Hmβ radio recombination lines (RRLs). Henα and Hemβ RRL emission is detected with the same n and m as those from the hydrogen RRLs only towards LOS+0.693. RRLs probe gas with positive and negative velocities towards the two Sgr A sources. The Hmβ to Hnα ratios reveal that the ionized gas is emitted under local thermodynamic equilibrium conditions in these regions. We find a He to H mass fraction of 0.29±0.01 consistent with the typical GC value, supporting the idea that massive stars have increased the He abundance compared to its primordial value. Physical properties are derived for the studied sources. We propose that the negative velocity component of both Sgr A sources is part of gas streams considered previously to model the GC cloud kinematics. Associated massive stars with what are presumably the closest H II regions to LOS-0.11 (positive velocity gas), LOS-0.02, and LOS+0.693 could be the main sources of ultraviolet photons ionizing the gas. The negative velocity components of both Sgr A sources might be ionized by the same massive stars, but only if they are in the same gas stream.

Abstract Copyright: © 2018 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society

Journal keyword(s): ISM: clouds - H II regions - Galaxy: centre

Simbad objects: 24

goto Full paper

goto View the reference in ADS

Number of rows : 24

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
#notes
1 NAME Sgr A Region reg 17 45 12 -28 48.3           ~ 911 0
2 MSX6C G359.9845+00.0275 HII 17 45 28.6 -28 56 03           ~ 14 0
3 [HJB85] Sgr A-H3 Rad 17 45 29.9 -28 54 36           ~ 12 0
4 GAL 000.012+00.12 HII 17 45 32.1 -28 56 13           ~ 15 0
5 GAL 000.02+00.04 HII 17 45 33.4 -28 54 08           ~ 12 0
6 NAME Sgr A-G Cld 17 45 37.9 -29 05 46           ~ 17 0
7 [HJB85] Sgr A-H5 Rad 17 45 38.5 -28 53 28           ~ 17 0
8 GCM -0.11 -0.08 MoC 17 45 39 -29 04.1           ~ 13 0
9 NAME Sgr A West HII 17 45 39.4 -29 00 24           ~ 347 0
10 NAME Sgr A* X 17 45 40.03599 -29 00 28.1699           ~ 3342 3
11 NAME Gal Center reg 17 45 40.04 -29 00 28.1           ~ 11246 0
12 NAME Sgr A East Rad 17 45 41 -29 00.8           ~ 436 2
13 NAME Sgr A-E Rad 17 45 41.131 -29 04 36.43           ~ 72 0
14 NAME Arched Filaments PoC 17 45 46.9 -28 50 39           ~ 45 1
15 [MML2011] G-0.02-0.07 HII 17 45.8 -28 59           ~ 4 0
16 GCM -0.02 -0.07 MoC 17 45 50.4 -28 59 06           ~ 138 0
17 NAME Sgr A D Em* 17 45 51.54 -29 00 23.2           ~ 19 0
18 NAME Sgr A A MoC 17 45 52.00 -28 59 26.2           ~ 34 0
19 NAME Sgr A B Rad 17 45 52.17 -28 59 36.4           ~ 17 0
20 NAME Sgr A C Rad 17 45 52.49 -29 00 00.0           ~ 14 0
21 NAME Sgr B2 (North) Rad 17 47 20.2 -28 22 21           ~ 504 1
22 NAME Sgr B2 MoC 17 47 20.4 -28 23 07           ~ 1879 1
23 GCM +0.693 -0.027 MoC 17 47 21.9 -28 21 27           ~ 14 0
24 NAME Sgr B2 HII L HII 17 47 22.739 -28 21 56.48           ~ 11 0

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2018MNRAS.476.2446A and select 'bookmark this link' or equivalent in the popup menu


2020.02.17-23:01:31

© Université de Strasbourg/CNRS

    • Contact