Publication

The feedback of an HC HII region on its parental molecular core. The case of core A1 in the star-forming region G24.78+0.08

Moscadelli, L., Rivilla, V. M., Cesaroni, R., Beltrán, M. T., Sánchez-Monge, Á., Schilke, P., Mottram, J. C., Ahmadi, A., Allen, V., Beuther, H., Csengeri, T., Etoka, S., Galli, D., Goddi, C., Johnston, K. G., Klaassen, P. D., Kuiper, R., Kumar, M. S. N., Maud, L. T., Möller, T., Peters, T., Van der Tak, F. & Vig, S., 17-Aug-2018, In : Astronomy & astrophysics. 616, August 2018, 22 p., A66.

Research output: Contribution to journalArticleAcademicpeer-review

APA

Moscadelli, L., Rivilla, V. M., Cesaroni, R., Beltrán, M. T., Sánchez-Monge, Á., Schilke, P., ... Vig, S. (2018). The feedback of an HC HII region on its parental molecular core. The case of core A1 in the star-forming region G24.78+0.08. Astronomy & astrophysics, 616(August 2018), [A66]. https://doi.org/10.1051/0004-6361/201832680

Author

Moscadelli, L. ; Rivilla, V. M. ; Cesaroni, R. ; Beltrán, M. T. ; Sánchez-Monge, Á. ; Schilke, P. ; Mottram, J. C. ; Ahmadi, A. ; Allen, V. ; Beuther, H. ; Csengeri, T. ; Etoka, S. ; Galli, D. ; Goddi, C. ; Johnston, K. G. ; Klaassen, P. D. ; Kuiper, R. ; Kumar, M. S. N. ; Maud, L. T. ; Möller, T. ; Peters, T. ; Van der Tak, F. ; Vig, S. / The feedback of an HC HII region on its parental molecular core. The case of core A1 in the star-forming region G24.78+0.08. In: Astronomy & astrophysics. 2018 ; Vol. 616, No. August 2018.

Harvard

Moscadelli, L, Rivilla, VM, Cesaroni, R, Beltrán, MT, Sánchez-Monge, Á, Schilke, P, Mottram, JC, Ahmadi, A, Allen, V, Beuther, H, Csengeri, T, Etoka, S, Galli, D, Goddi, C, Johnston, KG, Klaassen, PD, Kuiper, R, Kumar, MSN, Maud, LT, Möller, T, Peters, T, Van der Tak, F & Vig, S 2018, 'The feedback of an HC HII region on its parental molecular core. The case of core A1 in the star-forming region G24.78+0.08', Astronomy & astrophysics, vol. 616, no. August 2018, A66. https://doi.org/10.1051/0004-6361/201832680

Standard

The feedback of an HC HII region on its parental molecular core. The case of core A1 in the star-forming region G24.78+0.08. / Moscadelli, L.; Rivilla, V. M.; Cesaroni, R.; Beltrán, M. T.; Sánchez-Monge, Á.; Schilke, P.; Mottram, J. C.; Ahmadi, A.; Allen, V.; Beuther, H.; Csengeri, T.; Etoka, S.; Galli, D.; Goddi, C.; Johnston, K. G.; Klaassen, P. D.; Kuiper, R.; Kumar, M. S. N.; Maud, L. T.; Möller, T.; Peters, T.; Van der Tak, F.; Vig, S.

In: Astronomy & astrophysics, Vol. 616, No. August 2018, A66, 17.08.2018.

Research output: Contribution to journalArticleAcademicpeer-review

Vancouver

Moscadelli L, Rivilla VM, Cesaroni R, Beltrán MT, Sánchez-Monge Á, Schilke P et al. The feedback of an HC HII region on its parental molecular core. The case of core A1 in the star-forming region G24.78+0.08. Astronomy & astrophysics. 2018 Aug 17;616(August 2018). A66. https://doi.org/10.1051/0004-6361/201832680


BibTeX

@article{6643e91b4c3e4e7ea69696e9b554eaeb,
title = "The feedback of an HC HII region on its parental molecular core. The case of core A1 in the star-forming region G24.78+0.08",
abstract = "Context. G24.78+0.08 is a well known high-mass star-forming region, where several molecular cores harboring OB young stellar objects are found inside a clump of size ≈1 pc. This article focuses on the most prominent of these cores, A1, where an intense hypercompact (HC) HII region has been discovered by previous observations. Aims: Our aim is to determine the physical conditions and the kinematics of core A1, and study the interaction of the HII region with the parental molecular core. Methods: We combine ALMA 1.4 mm high-angular resolution (≈0.''2) observations of continuum and line emission with multi-epoch Very Long Baseline Interferometry data of water 22 GHz and methanol 6.7 GHz masers. These observations allow us to study the gas kinematics on linear scales from 10 to 104 au, and to accurately map the physical conditions of the gas over core A1. Results: The 1.4 mm continuum is dominated by free-free emission from the intense HC HII region (size ≈1000 au) observed to the North of core A1 (region A1N). Analyzing the H30α line, we reveal a fast bipolar flow in the ionized gas, covering a range of LSR velocities (VLSR) of ≈60 km s-1. The amplitude of the VLSR gradient, 22 km s-1 mpc-1, is one of the highest so far observed towards HC HII regions. Water and methanol masers are distributed around the HC HII region in A1N, and the maser three-dimensional (3D) velocities clearly indicate that the ionized gas is expanding at high speed (≥200 km s-1) into the surrounding molecular gas. The temperature distribution (in the range 100-400 K) over core A1, traced with molecular (CH3OCHO, 13CH3CN, 13CH3OH, and CH3CH2CN) transitions with level energy in the range 30 K ≤ Eu/k ≤ 300 K, reflects the distribution of shocks produced by the fast-expansion of the ionized gas of the HII region. The high-energy (550 K ≤ Eu/k ≤ 800 K) transitions of vibrationally excited CH3CN are likely radiatively pumped, and their rotational temperature can significantly differ from the kinetic temperature of the gas. Over core A1, the VLSR maps from both the 1.4 mm molecular lines and the 6.7 GHz methanol masers consistently show a VLSR gradient (amplitude ≈0.3 km s-1 mpc-1) directed approximately S-N. Rather than gravitationally supported rotation of a massive toroid, we interpret this velocity gradient as a relatively slow expansion of core A1.",
keywords = "techniques: interferometric, masers, ISM: jets and outflows, ISM: molecules, radio continuum: ISM, YOUNG STELLAR OBJECTS, MASER OBSERVATIONS, GAS, PARAMETERS, OUTFLOWS, CH3CN, VLA",
author = "L. Moscadelli and Rivilla, {V. M.} and R. Cesaroni and Beltr{\'a}n, {M. T.} and {\'A}. S{\'a}nchez-Monge and P. Schilke and Mottram, {J. C.} and A. Ahmadi and V. Allen and H. Beuther and T. Csengeri and S. Etoka and D. Galli and C. Goddi and Johnston, {K. G.} and Klaassen, {P. D.} and R. Kuiper and Kumar, {M. S. N.} and Maud, {L. T.} and T. M{\"o}ller and T. Peters and {Van der Tak}, F. and S. Vig",
year = "2018",
month = "8",
day = "17",
doi = "10.1051/0004-6361/201832680",
language = "English",
volume = "616",
journal = "Astronomy & astrophysics",
issn = "0004-6361",
publisher = "EDP Sciences",
number = "August 2018",

}

RIS

TY - JOUR

T1 - The feedback of an HC HII region on its parental molecular core. The case of core A1 in the star-forming region G24.78+0.08

AU - Moscadelli, L.

AU - Rivilla, V. M.

AU - Cesaroni, R.

AU - Beltrán, M. T.

AU - Sánchez-Monge, Á.

AU - Schilke, P.

AU - Mottram, J. C.

AU - Ahmadi, A.

AU - Allen, V.

AU - Beuther, H.

AU - Csengeri, T.

AU - Etoka, S.

AU - Galli, D.

AU - Goddi, C.

AU - Johnston, K. G.

AU - Klaassen, P. D.

AU - Kuiper, R.

AU - Kumar, M. S. N.

AU - Maud, L. T.

AU - Möller, T.

AU - Peters, T.

AU - Van der Tak, F.

AU - Vig, S.

PY - 2018/8/17

Y1 - 2018/8/17

N2 - Context. G24.78+0.08 is a well known high-mass star-forming region, where several molecular cores harboring OB young stellar objects are found inside a clump of size ≈1 pc. This article focuses on the most prominent of these cores, A1, where an intense hypercompact (HC) HII region has been discovered by previous observations. Aims: Our aim is to determine the physical conditions and the kinematics of core A1, and study the interaction of the HII region with the parental molecular core. Methods: We combine ALMA 1.4 mm high-angular resolution (≈0.''2) observations of continuum and line emission with multi-epoch Very Long Baseline Interferometry data of water 22 GHz and methanol 6.7 GHz masers. These observations allow us to study the gas kinematics on linear scales from 10 to 104 au, and to accurately map the physical conditions of the gas over core A1. Results: The 1.4 mm continuum is dominated by free-free emission from the intense HC HII region (size ≈1000 au) observed to the North of core A1 (region A1N). Analyzing the H30α line, we reveal a fast bipolar flow in the ionized gas, covering a range of LSR velocities (VLSR) of ≈60 km s-1. The amplitude of the VLSR gradient, 22 km s-1 mpc-1, is one of the highest so far observed towards HC HII regions. Water and methanol masers are distributed around the HC HII region in A1N, and the maser three-dimensional (3D) velocities clearly indicate that the ionized gas is expanding at high speed (≥200 km s-1) into the surrounding molecular gas. The temperature distribution (in the range 100-400 K) over core A1, traced with molecular (CH3OCHO, 13CH3CN, 13CH3OH, and CH3CH2CN) transitions with level energy in the range 30 K ≤ Eu/k ≤ 300 K, reflects the distribution of shocks produced by the fast-expansion of the ionized gas of the HII region. The high-energy (550 K ≤ Eu/k ≤ 800 K) transitions of vibrationally excited CH3CN are likely radiatively pumped, and their rotational temperature can significantly differ from the kinetic temperature of the gas. Over core A1, the VLSR maps from both the 1.4 mm molecular lines and the 6.7 GHz methanol masers consistently show a VLSR gradient (amplitude ≈0.3 km s-1 mpc-1) directed approximately S-N. Rather than gravitationally supported rotation of a massive toroid, we interpret this velocity gradient as a relatively slow expansion of core A1.

AB - Context. G24.78+0.08 is a well known high-mass star-forming region, where several molecular cores harboring OB young stellar objects are found inside a clump of size ≈1 pc. This article focuses on the most prominent of these cores, A1, where an intense hypercompact (HC) HII region has been discovered by previous observations. Aims: Our aim is to determine the physical conditions and the kinematics of core A1, and study the interaction of the HII region with the parental molecular core. Methods: We combine ALMA 1.4 mm high-angular resolution (≈0.''2) observations of continuum and line emission with multi-epoch Very Long Baseline Interferometry data of water 22 GHz and methanol 6.7 GHz masers. These observations allow us to study the gas kinematics on linear scales from 10 to 104 au, and to accurately map the physical conditions of the gas over core A1. Results: The 1.4 mm continuum is dominated by free-free emission from the intense HC HII region (size ≈1000 au) observed to the North of core A1 (region A1N). Analyzing the H30α line, we reveal a fast bipolar flow in the ionized gas, covering a range of LSR velocities (VLSR) of ≈60 km s-1. The amplitude of the VLSR gradient, 22 km s-1 mpc-1, is one of the highest so far observed towards HC HII regions. Water and methanol masers are distributed around the HC HII region in A1N, and the maser three-dimensional (3D) velocities clearly indicate that the ionized gas is expanding at high speed (≥200 km s-1) into the surrounding molecular gas. The temperature distribution (in the range 100-400 K) over core A1, traced with molecular (CH3OCHO, 13CH3CN, 13CH3OH, and CH3CH2CN) transitions with level energy in the range 30 K ≤ Eu/k ≤ 300 K, reflects the distribution of shocks produced by the fast-expansion of the ionized gas of the HII region. The high-energy (550 K ≤ Eu/k ≤ 800 K) transitions of vibrationally excited CH3CN are likely radiatively pumped, and their rotational temperature can significantly differ from the kinetic temperature of the gas. Over core A1, the VLSR maps from both the 1.4 mm molecular lines and the 6.7 GHz methanol masers consistently show a VLSR gradient (amplitude ≈0.3 km s-1 mpc-1) directed approximately S-N. Rather than gravitationally supported rotation of a massive toroid, we interpret this velocity gradient as a relatively slow expansion of core A1.

KW - techniques: interferometric

KW - masers

KW - ISM: jets and outflows

KW - ISM: molecules

KW - radio continuum: ISM

KW - YOUNG STELLAR OBJECTS

KW - MASER OBSERVATIONS

KW - GAS

KW - PARAMETERS

KW - OUTFLOWS

KW - CH3CN

KW - VLA

U2 - 10.1051/0004-6361/201832680

DO - 10.1051/0004-6361/201832680

M3 - Article

VL - 616

JO - Astronomy & astrophysics

JF - Astronomy & astrophysics

SN - 0004-6361

IS - August 2018

M1 - A66

ER -

ID: 77821270