2010A&A...510A..32M


Query : 2010A&A...510A..32M

2010A&A...510A..32M - Astronomy and Astrophysics, volume 510, A32-32 (2010/2-1)

Near-IR integral field spectroscopy of ionizing stars and young stellar objects on the borders of H II regions.

MARTINS F., POMARES M., DEHARVENG L., ZAVAGNO A. and BOURET J.C.

Abstract (from CDS):

We study three Galactic HII regions - RCW 79, RCW 82, and RCW 120 - where triggered star formation is taking place. Two stellar populations are observed: the ionizing stars of each HII region and young stellar objects on their borders. Our goal is to show that they represent two distinct populations, as expected from successive star-forming events. We use near-infrared integral field spectroscopy obtained with SINFONI on the VLT to make a spectral classification. We derived the stellar and wind properties of the ionizing stars using atmosphere models computed with the code CMFGEN. The young stellar objects were classified according to their K-band spectra. In combination with published near and mid infrared photometry, we constrained their nature. Linemaps were constructed to study the geometry of their close environment. We identify the ionizing stars of each region. RCW 79 is dominated by a cluster of a dozen O stars, identified for the first time by our observations. RCW 82 and RCW 120 are ionized by two and one O star, respectively. All ionizing stars are early-to-late O stars, close to the main sequence. The cluster ionizing RCW 79 formed 2.3±0.5Myr ago. Similar ages are estimated, albeit with a larger uncertainty, for the ionizing stars of the other two regions. The total mass-loss rate and ionizing flux is derived for each region. In RCW 79, where the richest cluster of ionizing stars is found, the mechanical wind luminosity represents only 0.1% of the ionizing luminosity, questioning the influence of stellar winds on the dynamics of these three HII regions. The young stellar objects show four main types of spectral features: H2 emission, Brγ emission, CO bandheads emission, and CO bandheads absorption. These features are typical of young stellar objects surrounded by disks and/or envelopes, confirming that star formation is taking place on the borders of the three HII regions. The radial velocities of most YSOs are consistent with that of the ionized gas, firmly establishing their association with the HII regions. Exceptions are found in RCW 120 where differences up to 50km/s are observed. Outflows are detected in a few YSOs. All YSOs have moderate-to-strong near-IR excess. In the [24] versus K-[24] diagram, the majority of the sources dominated by H2 emission lines stand out as redder and brighter than the rest of the YSOs. The quantitative analysis of their spectra indicates that, for most of them, the H2 emission is essentially thermal and likely produced by shocks. We tentatively propose that they represent an earlier phase of evolution compared to sources dominated by Brγ and CO bandheads. We suggest that they still possess a dense envelope in which jets or winds create shocks. The other YSOs have partly lost their envelopes and show signatures of accretion disks. Overall, the YSOs show distinct spectroscopic signatures compared to the ionizing sources, confirming the presence of two stellar populations.

Abstract Copyright:

Journal keyword(s): stars: early-type - HII regions - stars: formation - stars: winds, outflows - ISM: bubbles - stars: fundamental parameters

Nomenclature: Fig. 4, Table 1: [MPD2010] RCW79 NNa, [MPD2010] RCW79 NNww, [MPD2010] RCW79 NNwN, [MPD2010] RCW79 CHII 6, N=23. Table 1: [MPD2010] RCW120 e N=1.

Simbad objects: 66

goto Full paper

goto View the references in ADS

Number of rows : 66
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2024
#notes
1 M 42 HII 05 35 17 -05 23.4           ~ 4071 0
2 V* V1647 Ori Or* 05 46 13.1370578472 -00 06 04.885093296     18.1     M3.9 285 1
3 NAME McNeil Nebula RNe 05 46 14 -00 05.8           ~ 74 2
4 NAME Rosette Nebula HII 06 32 26.76 +04 47 37.1           ~ 492 1
5 [ZDC2006] Condensation 4 1 * 13 39 53.6639597904 -61 41 19.192170120           ~ 2 0
6 GRS G308.60 +00.60 HII 13 39.9 -61 45           ~ 101 0
7 [ZDC2006] Condensation 4 mm 13 39 54.00 -61 41 04.2           ~ 2 0
8 2MASS J13395600-6140590 NIR 13 39 56.001 -61 40 59.06           ~ 2 0
9 2MASS J13400894-6141389 NIR 13 40 08.9410928256 -61 41 38.971278276           ~ 2 0
10 [MPD2010] RCW79 1 * 13 40 09.11 -61 43 51.9           OBe 1 0
11 [MPD2010] RCW79 2 * 13 40 09.7759955939 -61 43 49.695482725           O7.5-8V/III 3 0
12 [MPD2010] RCW79 6b * 13 40 11.1298224033 -61 43 29.172224599           O9-B2V 2 0
13 [MPD2010] RCW79 10w3 * 13 40 11.3207155736 -61 43 59.717452555           B1-2 2 0
14 [MPD2010] RCW79 6c * 13 40 11.3460095166 -61 43 30.373370593           ~ 3 0
15 [MPD2010] RCW79 6a * 13 40 11.6319284470 -61 43 30.079912750           O6-8V/III 3 0
16 [MPD2010] RCW79 10w2 * 13 40 11.79 -61 43 57.8           B0-2.5V 1 0
17 [MPD2010] RCW79 8b * 13 40 11.9763702989 -61 43 32.223382240           O9-B2V/III 1 0
18 [MPD2010] RCW79 8a LP? 13 40 12.1448139847 -61 43 32.378234086           O9-B2V/III 2 0
19 [MPD2010] RCW79 10w1 * 13 40 12.1887112308 -61 43 56.914281354           B0-2.5V 3 0
20 [MPD2010] RCW79 12b * 13 40 12.19 -61 44 04.9           O9-B2V/III 1 0
21 [MPD2010] RCW79 5a * 13 40 12.3389116872 -61 43 47.184053628           O4-6V/III 4 0
22 [MPD2010] RCW79 12a * 13 40 12.42 -61 44 04.2           ~ 1 0
23 [MPD2010] RCW79 9c * 13 40 12.56 -61 43 29.5           B 1 0
24 [MPD2010] RCW79 10 * 13 40 12.6972216575 -61 43 58.349238608           O6.5-8V/III 2 0
25 [MPD2010] RCW79 4a * 13 40 12.7504528812 -61 44 15.494717119           O4-6V/III 3 0
26 [MPD2010] RCW79 7 * 13 40 13.0742187070 -61 43 47.254821358           O6-8V/III 3 0
27 [MPD2010] RCW79 9b * 13 40 13.0970232194 -61 43 28.069089741           O9-B2V/III 3 0
28 [MPD2010] RCW79 9a * 13 40 13.2119626041 -61 43 30.226998993           O9-B2V/III 3 0
29 [MPD2010] RCW79 4b * 13 40 13.2263693280 -61 44 16.613456683           ~ 3 0
30 [MPD2010] RCW79 10ne * 13 40 13.44 -61 43 53.9           Be 1 0
31 [MPD2010] RCW79 11 * 13 40 13.44 -61 43 41.0           ~ 1 0
32 2MASS J13402653-6147559 AB? 13 40 26.537 -61 47 55.98           ~ 3 0
33 2MASS J13403264-6147201 * 13 40 32.6483433744 -61 47 20.216606064           ~ 2 0
34 [MPD2010] RCW79 CHII 6 * 13 40 53.71 -61 45 46.8           O7.5-9.5V/III 1 0
35 [ZDC2006] Condensation 2 91 * 13 40 57.6 -61 45 44           ~ 2 0
36 2MASS J13405829-6146508 AB? 13 40 58.297 -61 46 50.88           ~ 3 0
37 [ZDC2006] Condensation 2 186 * 13 40 58.5 -61 46 48           ~ 2 0
38 [ZDC2006] Condensation 2 89 * 13 40 58.7 -61 46 52           ~ 2 0
39 [ZDC2006] Condensation 2 237 * 13 41 02.3 -61 44 16           ~ 2 0
40 RCW 82 HII 13 59.3 -61 27           ~ 30 0
41 2MASS J13592742-6123194 * 13 59 27.43 -61 23 19.5           ~ 2 0
42 2MASS J13592814-6122592 * 13 59 28.1533006080 -61 22 59.207995704         11.04 ~ 3 0
43 TYC 9004-2395-1 * 13 59 29.2026485568 -61 23 03.119388720   11.96 11.39     ~ 3 0
44 WRAY 15-1157 Em* 13 59 29.9442041304 -61 23 07.666424232       13.854 11.73 ~ 3 0
45 2MASS J13593474-6119224 Y*O 13 59 34.745 -61 19 22.49           ~ 2 0
46 2MASS J13593676-6120484 Y*O 13 59 36.77 -61 20 48.4           ~ 2 0
47 2MASS J13594736-6122017 Y*? 13 59 47.362 -61 22 01.74           ~ 3 0
48 [PZD2009] Star 35 * 13 59 50.890 -61 25 22.23           ~ 2 0
49 2MASS J13595761-6124368 * 13 59 57.61 -61 24 36.9           ~ 3 0
50 IRAS 17084-3816 Y*O 17 11 50.705 -38 19 55.34           ~ 6 0
51 2MASS J17120091-3831400 Y*O 17 12 00.920 -38 31 40.02           ~ 4 0
52 2MASS J17120796-3830513 Y*? 17 12 07.970 -38 30 51.39           ~ 3 0
53 [MPD2010] RCW120 e * 17 12 20.82 -38 29 25.5           O6-8V/III 1 0
54 CD-38 11636 * 17 12 20.8455264407 -38 29 30.394099276 12 11.90 10.87 10.42   O8 45 1
55 SH 2-3 HII 17 12.4 -38 28           ~ 205 1
56 2MASS J17122839-3830488 Y*O 17 12 28.395 -38 30 48.86           ~ 3 0
57 2MASS J17123365-3819523 Y*O 17 12 33.652 -38 19 52.32           ~ 5 0
58 2MASS J17124017-3820310 LP* 17 12 40.1765354016 -38 20 31.080933240           ~ 6 0
59 2MASS J17124082-3827295 Y*O 17 12 40.8301254072 -38 27 29.578567788           ~ 4 0
60 2MASS J17124110-3827171 Y*O 17 12 41.1105490464 -38 27 17.171019864           ~ 6 0
61 2MASS J17124216-3826578 Y*O 17 12 42.166 -38 26 57.87           ~ 4 0
62 2MASS J17124603-3825247 Y*O 17 12 46.034 -38 25 24.72           ~ 6 0
63 * c Oph Be* 17 31 24.9538710166 -23 57 45.514802684 4.75 4.81 4.81 4.74 4.72 A0V 273 0
64 NAME Galactic Center reg 17 45 39.60213 -29 00 22.0000           ~ 14383 0
65 NGC 6618 OpC 18 20 47 -16 10.3           ~ 1612 0
66 NAME Galactic Bulge reg ~ ~           ~ 4290 0

To bookmark this query, right click on this link: simbad:objects in 2010A&A...510A..32M and select 'bookmark this link' or equivalent in the popup menu