<i>Spitzer</i>IRAC and MIPS Imaging of Clusters and Outflows in Nine High‐Mass Star Forming Regions

Qiu, Keping; Zhang, Qizhou; Megeath, S. Thomas; Gutermuth, Robert; Beuther, H.; Shepherd, D. S.; Sridharan, T. K.; Testi, L.; Pree, C. G. De

doi:10.1086/591044

Cited by 97 publications

(148 citation statements)

References 95 publications

(181 reference statements)

Supporting

Mentioning

138

Contrasting

Order By: Relevance

“…Qiu et al (2008) found five-band Spitzer/IRAC and 2MASS H and K s emission towards 4-n, as well as Spitzer/IRAC 3.6 μm, 4.5 μm, 5.8 μm, and 8.0 μm emission towards 1/2/3-n. Source 4-n is likely at an early stage of evolution, although it is probably the most evolved source in the northern (proto)cluster.…”

Section: Continuum Sourcesmentioning

confidence: 73%

“…We confirmed their estimation, finding that the visual extinction for 13-s is A v ∼ 2700 (see Table 2). Source 13-s is in an early stage of evolution, according to its NIR excess and the presence of H 2 O and Class ii CH 3 OH masers (Beuther et al 2002d), although the detection of a VLA 3.6 cm source at its position (Sridharan et al 2002), suggests that there is a recently ignited protostar that has already formed an ultracompact or hypercompact Hii region, the detected radio emission being consistent with an ionizing B2 V star (Martín-Hernández et al 2008;Qiu et al 2008;Panagia 1973).…”

Section: Continuum Sourcesmentioning

confidence: 98%

“…It has H 2 O and CH 3 OH maser emission (Sridharan et al 2002;Beuther et al 2002d) and X-ray sources (Beuther et al 2002a), indicating that there is ongoing formation of intermediate-to-high mass stars. The region is embedded within a cluster of over 800 components detected at NIR wavelengths (Martín-Hernández et al 2008;Qiu et al 2008), and it has a rich and energetic outflow component with multiple outflows detected in CO (Beuther et al 2002c(Beuther et al , 2003. Beuther et al (2002b) found that the large-scale mm emission shows two massive gas clumps roughly aligned in a north-south direction that splits into several subsources with increasing spatial resolution (Beuther & Schilke 2004).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Fragmentation in the massive star-forming region IRAS 19410+2336

Rodón

Beuther

Schilke

2012

A&A

View full text Add to dashboard Cite

Context. The core mass functions (CMFs) of low-mass star-forming regions are found to resemble the shape of the initial mass function (IMF). A similar result is observed for the dust clumps in high-mass star-forming regions, although on spatial scales of clusters that do not resolve the substructure that is found in these massive clumps. The region IRAS 19410+2336 is one exception, having been observed on spatial scales on the order of ∼2500 AU, which are sufficient to resolve the clump substructure into individual cores. Aims. We investigate the protostellar content of IRAS 19410+2336 at high spatial resolution at 1.4 mm, determining the temperature structure of the region and deriving its CMF. Methods. The massive star-forming region IRAS 19410+2336 was mapped with the PdBI (BCD configurations) at 1.4 mm and 3 mm in the continuum and several transitions of formaldehyde (H 2 CO) and methyl cyanide (CH 3 CN). The H 2 CO transitions were also observed with the IRAM 30 m Telescope. Results. We detect 26 continuum sources at 1.4 mm with a spatial resolution as low as ∼2200 AU, several of them with counterparts at near-and mid-infrared wavelengths, distributed in two (proto)clusters. With the PdBI CH 3 CN and PdBI/IRAM 30 m H 2 CO emission, we derive the temperature structure of the region, ranging from 35 K to 90 K. Using these temperatures, we calculate the core masses of the detected sources, ranging from ∼0.7 M to ∼8 M . These masses are strongly affected by the spatial filtering of the interferometer, which removes a common envelope with ∼90% of the single-dish flux. Considering only the detected dense cores and accounting for binning effects as well as cumulative distributions, we derive a CMF, with a power-law index β = −2.3 ± 0.2. We resolve the Jeans length of the (proto)clusters by one order of magnitude, and only find a small velocity dispersion between the different subsources. Conclusions. Since we cannot unambiguously differentiate between protostellar and prestellar cores, the derived CMF is not prestellar. Furthermore, because of the large fraction of missing flux, we cannot establish a firm link between the CMF and the IMF. This implies that future high-mass CMF studies will need to complement the interferometer continuum data with the short spacing information, a task suitable for ALMA. We note that the method of extracting temperatures using H 2 CO lines becomes less applicable when reaching the dense core scales of the interferometric observations because most of the H 2 CO appears to originate in the envelope structure.

show abstract

Section: Continuum Sourcesmentioning

confidence: 73%

Section: Continuum Sourcesmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Fragmentation in the massive star-forming region IRAS 19410+2336

Rodón

Beuther

Schilke

2012

A&A

View full text Add to dashboard Cite

show abstract

“…For comparison, we also show (in Fig. 4b) the NH 3 (1, 1) integrated intensity map from Zhang et al (2002) overlaid with the cluster of infrared sources reported in recent studies (Hunter et al 1995;Chen et al 2005;Qiu et al 2008) in order to have a complete view of the stellar content in AFGL 5142. The overall structure of the integrated N 2 H + (1-0) emission consists of two main cores, located to the west and to the east of the dust condensation (hereafter western and eastern cores), surrounded by a more extended structure with an X-shape morphology, roughly following the same morphology as the NH 3 emission.…”

Section: Molecular Line Emission: N 2 H +mentioning

confidence: 99%

“…Recently, Qiu et al (2008) carried out Spitzer Space Telescope IRAC and MIPS observations toward AFGL 5142. The authors identify 44 YSOs, 20 of them clustered around the central massive star and surrounded by a more extended and sparse distribution of young stars and protostars.…”

Section: Introductionmentioning

confidence: 99%

N₂H⁺depletion in the massive protostellar cluster AFGL 5142

Busquet

Estalella

Zhang

et al. 2010

A&A

View full text Add to dashboard Cite

Aims. We aim at investigating the NH 3 /N 2 H + abundance ratio toward the high-mass star-forming region AFGL 5142 with high angular resolution in order to study whether the NH 3 /N 2 H + ratio behaves similarly to the low-mass case, for which the ratio decreases from starless cores to cores associated with young stellar objects (YSOs). Methods. CARMA was used to observe the 3.2 mm continuum and N 2 H + (1-0) emission toward AFGL 5142. We used NH 3 (1, 1) and (2, 2), as well as HCO + (1-0) and H 13 CO + (1-0) data available from the literature, to study the chemical environment. Additionally, we performed a time-dependent chemical modeling of the region. Results. The 3.2 mm continuum emission reveals a dust condensation of ∼23 M associated with the massive YSOs, deeply embedded in the strongest NH 3 core (hereafter central core). The dense gas emission traced by N 2 H + reveals two main cores, the western core of ∼0.08 pc in size and the eastern core of ∼0.09 pc, surrounded by a more extended and complex structure of ∼0.5 pc, mimicking the morphology of the NH 3 emission. The two cores are located to the west and to the east of the 3.2 mm dust condensation. Toward the central core the N 2 H + emission drops significantly, indicating a clear chemical differentiation in the region. The N 2 H + column density in the central core is one order of magnitude lower than in the western and eastern cores. Furthermore, we found low values of the NH 3 /N 2 H + abundance ratio ∼50-100 toward the western and eastern cores and high values up to 1000 associated with the central core. The chemical model used to explain the differences seen in the NH 3 /N 2 H + ratio indicates that density along with temperature is a key parameter in determining the abundances of both NH 3 and N 2 H + . The high density (n 10 6 cm −3 ) and temperature (T 70 K) reached in the central core allow molecules such as CO to evaporate from grain mantles. The CO desorption causes a significant destruction of N 2 H + , which favors the formation of HCO + . This result is supported by our observations, which show that N 2 H + and HCO + are anticorrelated in the central core. The observed values of the NH 3 /N 2 H + ratio in the central core can be reproduced by our model for times of t 4.5−5.3 × 10 5 yr, while in the western and eastern cores the NH 3 /N 2 H + ratio can be reproduced by our model for times in the range 10 4 −3 × 10 6 yr. Conclusions. The NH 3 /N 2 H + abundance ratio in AFGL 5142 does not follow the same trend as in regions of low-mass star formation mainly because of the high temperature reached in hot cores.

show abstract