Millimeter methanol emission in the high-mass young stellar object G24.33+0.14-Reference-Cited by-同舟云学术

Millimeter methanol emission in the high-mass young stellar object G24.33+0.14

Published:2022-09-05 Issue:5 Volume:74 Page:1234-1262
ISSN:0004-6264
Container-title:Publications of the Astronomical Society of Japan
language:en
Short-container-title:

Author:

Hirota Tomoya¹²^ORCID,Wolak Pawel³,Hunter Todd R⁴⁵,Brogan Crystal L⁴,Bartkiewicz Anna³,Durjasz Michal³,Kobak Agnieszka³,Olech Mateusz⁶,Szymczak Marian³,Burns Ross A¹⁷^ORCID,Aberfelds Artis⁸^ORCID,Baek Giseon⁹,Brand Jan¹⁰^ORCID,Breen Shari¹¹,Byun Do-Young⁷,Caratti o Garatti Alessio¹²,Chen Xi¹³,Chibueze James O¹⁴¹⁵^ORCID,Cyganowski Claudia¹⁶^ORCID,Eislöffel Jochen¹⁷,Ellingsen Simon¹⁸^ORCID,Hirano Naomi¹⁹^ORCID,Hu Bo²⁰²¹,Kang Ji-hyun⁷,Kim Jeong-Sook²²,Kim Jungha⁷,Kim Kee-Tae⁷,Kim Mi Kyoung²³,Kramer Busaba²⁴²⁵^ORCID,Lee Jeong-Eun⁹,Linz Hendrik²⁶,Liu Tie²⁷,MacLeod Gordon²⁸²⁹,McCarthy Tiege P¹⁸^ORCID,Menten Karl²⁴,Motogi Kazuhito³⁰^ORCID,Oh Chung-Sik⁷,Orosz Gabor¹⁸³¹^ORCID,Sobolev Andrey M³²^ORCID,Stecklum Bringfried¹⁷,Sugiyama Koichiro¹²⁵,Sunada Kazuyoshi³³³⁴,Uscanga Lucero³⁵^ORCID,van den Heever Fanie²⁹,Volvach Alexandr E³⁶,Volvach Larisa N³⁶,Wu Yuan Wei³⁷^ORCID,Yonekura Yoshinori³⁸^ORCID

Affiliation:

1. National Astronomical Observatory of Japan , 2-21-1 Osawa, Mitaka-shi, Tokyo 181-8588, Japan

2. Department of Astronomical Sciences, SOKENDAI (The Graduate University for Advanced Studies) , 2-21-1 Osawa, Mitaka-shi, Tokyo 181-8588, Japan

3. Institute of Astronomy, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University , Grudziadzka 5, PL-87-100 Torun, Poland

4. NRAO , 520 Edgemont Road, Charlottesville, VA 22903, USA

5. Center for Astrophysics | Harvard-Smithsonian , 60 Garden Street, Cambridge, MA 02138, USA

6. Space Radio-Diagnostic Research Center, Faculty of Geoengineering, University of Warmia and Mazury , Olsztyn 10-710, Poland

7. Korea Astronomy and Space Science Institute , 776 Daedeokdaero, Yuseong, Daejeon 34055, Republic of Korea

8. Engineering Research Institute, Ventspils International Radio Astronomy Center, Ventspils University of Applied Sciences , Inzenieru Str. 101, Ventspils, LV-3601, Latvia

9. School of Space Research, Kyung Hee University , 1732, Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do 17104, Republic of Korea

10. INAF-Istituto di Radioastronomia and Italian ALMA Regional Centre , via P. Gobetti 101, 40129 Bologna, Italy

11. SKAO, Jodrell Bank, Lower Withington, Macclesfield , Cheshire SK11 9FT, UK

12. INAF-Osservatorio Astronomico di Capodimonte , Salita Moiariello, 16, 80131, Napoli, Italy

13. Center for Astrophysics, Guangzhou University , Guangzhou 510006, China

14. Centre for Space Research, Physics Department, North-West University , Potchefstroom 2520, South Africa

15. Department of Physics and Astronomy, Faculty of Physical Sciences, University of Nigeria , Carver Building, 1 University Road, Nsukka, Nigeria

16. SUPA, School of Physics and Astronomy, University of St. Andrews , North Haugh, St. Andrews KY16 9SS, UK

17. Thüringer Landessternwarte , Sternwarte 5, 07778 Tautenburg, Germany

18. School of Natural Sciences, University of Tasmania , Private Bag 37, Hobart, Tasmania 7001, Australia

19. Institute of Astronomy and Astrophysics, Academia Sinica , 11F of Astronomy-Mathematics Building, AS/NTU, No.1, Sec. 4 , Roosevelt Rd, Taipei 10617, Taiwan

20. School of Astronomy and Space Science, Nanjing University , 163 Xianlin Avenue, Nanjing 210023, China

21. Key Laboratory of Modern Astronomy and Astrophysics (Nanjing University), Ministry of Education , Nanjing 210023, China

22. Ulsan National Institute of Science and Technology UNIST-gil 50 , Eonyang-eup, Ulju-gun, Ulsan 44919, Republic of Korea

23. Department of Child Studies, Faculty of Home Economics, Otsuma Women’s University , 12 Sanban-cho, Chiyoda-ku, Tokyo 102-8357, Japan

24. Max-Planck-Institut für Radioastronomie , Auf dem Hügel 69, 53121 Bonn, Germany

25. National Astronomical Research Institute of Thailand (Public Organization) , 260 Moo 4, T. Donkaew, Amphur Maerim, Chiang Mai, 50180, Thailand

26. Max-Planck-Institut für Astronomie , Königstuhl 17, D-69117 Heidelberg, Germany

27. Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Chinese Academy of Sciences , 80 Nandan Road, Shanghai 200030, China

28. The University of Western Ontario , 1151 Richmond Street, London, ON N6A 3K7, Canada

29. South African Radio Astronomy Observatory , Hartebeesthoek site, PO Box 443, Krugersdorp 1740, South Africa

30. Graduate School of Sciences and Technology for Innovation, Yamaguchi University , 1677-1 Yoshida, Yamaguchi, Yamaguchi 753-8512, Japan

31. Joint Institute for VLBI ERIC , Oude Hoogeveensedijk 4, 7991 PD Dwingeloo, Netherlands

32. Astronomical Observatory, Institute for Natural Sciences and Mathematics, Ural Federal University , 19 Mira street, Ekaterinburg, 620002, Russia

33. National Astronomical Observatory of Japan , Hoshigaoka 2-12, Mizusawa, Oshu-shi, Iwate 023-0861, Japan

34. Department of Astronomical Sciences, SOKENDAI (The Graduate University for Advanced Studies) , 2-12 Hoshigaoka, Mizusawa, Oshu-shi, Iwate 023-0861, Japan

35. Department of Astronomy , University of Guanajuato, Apartado Postal 144, 36000 Guanajuato, Gto, Mexico

36. Radio Astronomy and Geodynamics Department of Crimean Astrophysical Observatory , Katsively, RT-22 Crimea

37. National Time Service Center, Key Laboratory of Precise Positioning and Timing Technology, Chinese Academy of Sciences , Xi’an 710600, China

38. Center for Astronomy, Ibaraki University , 2-1-1 Bunkyo, Mito, Ibaraki 310-8512, Japan

Abstract

Abstract In 2019 September, a sudden flare of the 6.7 GHz methanol maser was observed toward the high-mass young stellar object (HMYSO) G24.33+0.14. This may represent the fourth detection of a transient mass accretion event in an HMYSO after S255IR NIRS3, NGC 6334I-MM1, and G358.93−0.03-MM1. G24.33+0.14 is unique among these sources as it clearly shows a repeating flare with an 8 yr interval. Using the Atacama Large Millimeter/submillimeter Array (ALMA), we observed the millimeter continuum and molecular lines toward G24.33+0.14 in the pre-flare phase in 2016 August (ALMA Cycle 3) and the mid-flare phase in 2019 September (ALMA Cycle 6). We identified three continuum sources in G24.33+0.14, and the brightest source, C1, which is closely associated with the 6.7 GHz maser emission, shows only a marginal increase in flux density with a flux ratio (Cycle 6$/$Cycle 3) of 1.16 ± 0.01, considering an additional absolute flux calibration uncertainty of $10\%$. We identified 26 transitions from 13 molecular species other than methanol, and they exhibit similar levels of flux differences with an average flux ratio of 1.12 ± 0.15. In contrast, eight methanol lines observed in Cycle 6 are brighter than those in Cycle 3 with an average flux ratio of 1.23 ± 0.13, and the higher excitation lines tend to show a larger flux increase. If this systematic increasing trend is real, it would suggest radiative heating close to the central HMYSO due to an accretion event which could expand the size of the emission region and/or change the excitation conditions. Given the low brightness temperatures and small flux changes, most of the methanol emission is likely to be predominantly thermal, except for the 229.759 GHz (8−1–70 E) line known as a class I methanol maser. The flux change in the millimeter continuum of G24.33+0.14 is smaller than in S255IR NIRS3 and NGC 6334I-MM1 but is comparable with that in G358.93−0.03-MM1, suggesting different amounts of accreted mass in these events.

Funder

NSF

NINS

NRC

NSC

KASI

ESO

University of California

Jet Propulsion Laboratory

California Institute of Technology

National Aeronautics and Space Administration

MEXT