Millimeter-wave molecular line observations of the tornado nebula

D. Sakai, Tomoharu Oka, Kunihiko Tanaka, S. Matsumura, K. Miura, S. Takekawa

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

We report the results of millimeter-wave molecular line observations of the Tornado Nebula (G357.7-0.1), which is a bright radio source behind the Galactic center region. A 15′ × 15′ area was mapped in the J = 1-0 lines of CO, 13CO, and HCO+ with the Nobeyama Radio Observatory 45 m telescope. The Very Large Array archival data of OH at 1720 MHz were also reanalyzed. We found two molecular clouds with separate velocities, V LSR = -14 km s-1 and +5 km s-1. These clouds show rough spatial anti-correlation. Both clouds are associated with OH 1720 MHz emissions in the area overlapping with the Tornado Nebula. The spatial and velocity coincidence indicates violent interaction between the clouds and the Tornado Nebula. Modestly excited gas prefers the position of the Tornado "head" in the -14 km s-1 cloud, also suggesting the interaction. Virial analysis shows that the +5 km s-1 cloud is more tightly bound by self-gravity than the -14 km s-1 cloud. We propose a formation scenario for the Tornado Nebula; the +5 km s-1 cloud collided into the -14 km s-1 cloud, generating a high-density layer behind the shock front, which activates a putative compact object by Bondi-Hoyle-Lyttleton accretion to eject a pair of bipolar jets.

Original languageEnglish
Article number49
JournalAstrophysical Journal
Volume791
Issue number1
DOIs
Publication statusPublished - 2014 Aug 10

Fingerprint

tornadoes
tornado
nebulae
millimeter waves
radio
Very Large Array (VLA)
shock fronts
molecular clouds
observatories
observatory
accretion
interactions
telescopes
gravity
gravitation

Keywords

  • ISM: clouds
  • ISM: individual objects (G357.7 0.1)
  • ISM: jets and outflows

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Millimeter-wave molecular line observations of the tornado nebula. / Sakai, D.; Oka, Tomoharu; Tanaka, Kunihiko; Matsumura, S.; Miura, K.; Takekawa, S.

In: Astrophysical Journal, Vol. 791, No. 1, 49, 10.08.2014.

Research output: Contribution to journalArticle

Sakai, D. ; Oka, Tomoharu ; Tanaka, Kunihiko ; Matsumura, S. ; Miura, K. ; Takekawa, S. / Millimeter-wave molecular line observations of the tornado nebula. In: Astrophysical Journal. 2014 ; Vol. 791, No. 1.
@article{4b4c23a71ee6470ebcda013e5a2de002,
title = "Millimeter-wave molecular line observations of the tornado nebula",
abstract = "We report the results of millimeter-wave molecular line observations of the Tornado Nebula (G357.7-0.1), which is a bright radio source behind the Galactic center region. A 15′ × 15′ area was mapped in the J = 1-0 lines of CO, 13CO, and HCO+ with the Nobeyama Radio Observatory 45 m telescope. The Very Large Array archival data of OH at 1720 MHz were also reanalyzed. We found two molecular clouds with separate velocities, V LSR = -14 km s-1 and +5 km s-1. These clouds show rough spatial anti-correlation. Both clouds are associated with OH 1720 MHz emissions in the area overlapping with the Tornado Nebula. The spatial and velocity coincidence indicates violent interaction between the clouds and the Tornado Nebula. Modestly excited gas prefers the position of the Tornado {"}head{"} in the -14 km s-1 cloud, also suggesting the interaction. Virial analysis shows that the +5 km s-1 cloud is more tightly bound by self-gravity than the -14 km s-1 cloud. We propose a formation scenario for the Tornado Nebula; the +5 km s-1 cloud collided into the -14 km s-1 cloud, generating a high-density layer behind the shock front, which activates a putative compact object by Bondi-Hoyle-Lyttleton accretion to eject a pair of bipolar jets.",
keywords = "ISM: clouds, ISM: individual objects (G357.7 0.1), ISM: jets and outflows",
author = "D. Sakai and Tomoharu Oka and Kunihiko Tanaka and S. Matsumura and K. Miura and S. Takekawa",
year = "2014",
month = "8",
day = "10",
doi = "10.1088/0004-637X/791/1/49",
language = "English",
volume = "791",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP Publishing Ltd.",
number = "1",

}

TY - JOUR

T1 - Millimeter-wave molecular line observations of the tornado nebula

AU - Sakai, D.

AU - Oka, Tomoharu

AU - Tanaka, Kunihiko

AU - Matsumura, S.

AU - Miura, K.

AU - Takekawa, S.

PY - 2014/8/10

Y1 - 2014/8/10

N2 - We report the results of millimeter-wave molecular line observations of the Tornado Nebula (G357.7-0.1), which is a bright radio source behind the Galactic center region. A 15′ × 15′ area was mapped in the J = 1-0 lines of CO, 13CO, and HCO+ with the Nobeyama Radio Observatory 45 m telescope. The Very Large Array archival data of OH at 1720 MHz were also reanalyzed. We found two molecular clouds with separate velocities, V LSR = -14 km s-1 and +5 km s-1. These clouds show rough spatial anti-correlation. Both clouds are associated with OH 1720 MHz emissions in the area overlapping with the Tornado Nebula. The spatial and velocity coincidence indicates violent interaction between the clouds and the Tornado Nebula. Modestly excited gas prefers the position of the Tornado "head" in the -14 km s-1 cloud, also suggesting the interaction. Virial analysis shows that the +5 km s-1 cloud is more tightly bound by self-gravity than the -14 km s-1 cloud. We propose a formation scenario for the Tornado Nebula; the +5 km s-1 cloud collided into the -14 km s-1 cloud, generating a high-density layer behind the shock front, which activates a putative compact object by Bondi-Hoyle-Lyttleton accretion to eject a pair of bipolar jets.

AB - We report the results of millimeter-wave molecular line observations of the Tornado Nebula (G357.7-0.1), which is a bright radio source behind the Galactic center region. A 15′ × 15′ area was mapped in the J = 1-0 lines of CO, 13CO, and HCO+ with the Nobeyama Radio Observatory 45 m telescope. The Very Large Array archival data of OH at 1720 MHz were also reanalyzed. We found two molecular clouds with separate velocities, V LSR = -14 km s-1 and +5 km s-1. These clouds show rough spatial anti-correlation. Both clouds are associated with OH 1720 MHz emissions in the area overlapping with the Tornado Nebula. The spatial and velocity coincidence indicates violent interaction between the clouds and the Tornado Nebula. Modestly excited gas prefers the position of the Tornado "head" in the -14 km s-1 cloud, also suggesting the interaction. Virial analysis shows that the +5 km s-1 cloud is more tightly bound by self-gravity than the -14 km s-1 cloud. We propose a formation scenario for the Tornado Nebula; the +5 km s-1 cloud collided into the -14 km s-1 cloud, generating a high-density layer behind the shock front, which activates a putative compact object by Bondi-Hoyle-Lyttleton accretion to eject a pair of bipolar jets.

KW - ISM: clouds

KW - ISM: individual objects (G357.7 0.1)

KW - ISM: jets and outflows

UR - http://www.scopus.com/inward/record.url?scp=84905283793&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84905283793&partnerID=8YFLogxK

U2 - 10.1088/0004-637X/791/1/49

DO - 10.1088/0004-637X/791/1/49

M3 - Article

VL - 791

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 1

M1 - 49

ER -