Sagittarius D

Sagittarius D
Molecular cloud
Giant molecular cloud
Observation data: J2000 epoch
Right ascension17h 48m 41.75s
Declination−28° 01′ 45.0″
ConstellationSagittarius
DesignationsGRS G001.05 -00.10, MGCS 001.05-00.1, MGCS 001.1-00.1, Sgr D, SNR G001.1-00.1
See also: Lists of nebulae

Sagittarius D (Sgr D) is a active star-forming region and radio source located 1° east of the galactic center. The radio source is consists of two major components; SNR G1.05-0.15 (Sagittarius D SNR) and G1.13-0.10 (Sagittarius D H II region). Data suggests that Sagittarius D is situated beyond the galactic center.

Sagittarius D is composed of supernova remnants (SNRs) that fuel star formation and the creation of masers. Giant molecular clouds cover most of the region, containing dense molecular cores rich in star formation.

Components

G1.13-0.10

G1.13-0.10 (Sagittarius D H II region) is a star-forming region situated north of the Sagittarius D SNR, Observations show that the H II region is dominated by a single radio source, which is surrounded by a 7 arcminute diameter halo of ionized material. Analysis of the ionized material having very narrow line widths and high velocity broad-line absorption features confirm that the Sagittarius D lies beyond the galactic center. Observations on OH and H2O masers indicate at least three sites of recent or ongoing star formation within the Sagittarius D H II region. The H2O masers seem to reside in high-velocity molecular outflows.

SNR G1.05-0.15

SNR G1.05-0.15 (Sagittarius D Supernova Remnant) is a non-thermal supernova remnant (SNR) located 5 arcminutes south of the Sagittarius D H II region. This remnant appears bright on the northern edge where it overlaps with the Sagittarius D H II region. A study found that it is the closest component to the sun based on absorption lines detected at -16 km s⁻¹. Its estimated shell radius of 4 to 5 arcminutes. The core of the SNR is designated as G1.05-0.14, an H II region and molecular cloud core that interacts with the giant molecular cloud of Sagittarius D.

Other Components

SNR G1.4-0.1 is a supernova remnant located 15 arcminutes northeast of the Sagittarius D H II region. The remnant is expanding into two molecular clouds. The supernova pushed its materials into the molecular clouds, this produced a rich maser environment. Observations detected over 40 class I methanol masers, hydroxyl masers, and ammonia emission clumps surrounding the SNR.

Using the Suzaku X-ray satellite, researchers identified an object north of the Sagittarius D H II region designated as G1.2-0.0. This object was first designated as a supernova remnant, this was based on thermal X-ray spectrum exhibiting highly ionized atoms and emission lines. Another observation later revealed strong low-frequency absorption and mid-infrared emission lines, reclassifying G1.2-0.0 as an H II region rather than a supernova remnant.

References

  1. 1 2 3 "NAME Sgr D". simbad.cds.unistra.fr.
  2. 1 2 3 4 Mehringer, David M.; Goss, W. M.; Lis, D. C.; Palmer, Patrick; Menten, Karl M. (January 1998). "VLA Observations of the Sagittarius D Star-Forming Region". The Astrophysical Journal. 493 (1): 274–290. Bibcode:1998ApJ...493..274M. doi:10.1086/305120.
  3. 1 2 3 Yusef-Zadeh, F.; Goss, W. M.; Roberts, D. A.; Robinson, B; Frail, D. A. (December 1999). "Three New Supernova Remnant OH Masers Near the Galactic Center: Evidence for Large-Scale Maser Emission from Supernova Remnants". THR Astrophysical Journal. 527 (1): 172–179. arXiv:astro-ph/9907370. Bibcode:1999ApJ...527..172Y. doi:10.1086/308087.
  4. ↑ Downes, D.; Wilson, T. L.; Bieging, J.; Wink, J. (June 1980). "H110alpha and H2CO survey of galactic radio sources". Astronomy and Astrophysics Supplement Series. 40: 379–394. Bibcode:1980A&AS...40..379D.
  5. ↑ Sidoli, L.; Mereghettu, S.; Treves, A.; Parmar, A. N.; Turolla, R.; Favata, F. (June 2001). "X-ray emission from the giant molecular clouds in the Galactic Center region and the discovery of new X-ray sources". Astronomy and Astrophysics. 372 (2): 651–662. arXiv:astro-ph/0104121. Bibcode:2001A&A...372..651S. doi:10.1051/0004-6361:20010503.
  6. ↑ Pihlström, Y. M.; Sjouwerman, L. O.; Frail, D. A.; Claussen, M. J.; Mesler, R. A.; McEwen, B. C. (April 2014). "Detection of Class I Methanol (CH3OH) Maser Candidates in Supernova Remnants". The Astronomical Journal. 147 (4): 73. arXiv:1312.6882. Bibcode:2014AJ....147...73P. doi:10.1088/0004-6256/147/4/73. 73.
  7. ↑ McEwen, Bridget C.; Pihlström, Ylva M.; Sjouwerman, Loránt O. (August 2016). "NH3(3,3) and CH3OH near Supernova Remnants: GBT and VLA Observations". The Astrophysical Journal. 826 (2): 189. arXiv:1606.01263. Bibcode:2016ApJ...826..189M. doi:10.3847/0004-637X/826/2/189. 189.
  8. ↑ Sawada, Makoto; Koyama, Katsuji; Tsujimoto, Masahiro; Law, Casey J.; Tsuru, Takeshi Go; Hyodo, Yoshiaki (January 2009). "X-Ray Observations of the Sagittarius D H II Region toward the Galactic Center with Suzaku". Publications of the Astronomical Society of Japan. 61 (SP1): S209–S218. Bibcode:2009PASJ...61S.209S. doi:10.1093/pasj/61.sp1.S209.
  9. ↑ Hurley-Walker, N.; Gaensler, B. M.; Leahy, D. A.; Filipović, M. D.; Hancock, P. J.; Franzen, T. M. O.; Offringa, A. R.; Callingham, J. R.; Hindson, L.; Wu, C.; Bell, M. E.; For, B.-Q.; Johnston-Hollitt, M.; Kapińska, A. D.; Morgan, J.; Murphy, T.; McKinley, B.; Procopio, P.; Staveley-Smith, L.; Wyath, R. B.; Zheng, Q. (November 2019). "Candidate radio supernova remnants observed by the GLEAM survey over 345° < l < 60° and 180° < l < 240°". Publications of the Astronomical Society of Australia. 36 e048. arXiv:1911.08124. Bibcode:2019PASA...36...48H. doi:10.1017/pasa.2019.33. e048.