No Water Masers Associated with Supernova Remnants

ABSTRACT We have performed 3D magnetohydrodynamics (MHD) numerical simulations with the aim of exploring the scenario in which the initial mass distribution of a supernova (SN) explosion is anisotropic. The purpose is to analyse if this scenario can also explain the radio-continuum emission and the expansion observed in young supernova remnants (SNRs). To study the expansion, synthetic polarized synchrotron emission maps were computed from the MHD simulations. We found a good agreement (under a number of assumptions) between this expansion study and previous observational results applied to Tycho’s SNR, which represents a good example of asymmetric young SNRs. Additionally, both the observed morphology and the brightness distribution are qualitatively reproduced.

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New optically identified supernova remnants in the Large Magellanic Cloud

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa3382 ◽

2020 ◽

Vol 500 (2) ◽

pp. 2336-2358

Author(s):

Miranda Yew ◽

Miroslav D Filipović ◽

Milorad Stupar ◽

Sean D Points ◽

Manami Sasaki ◽

...

Keyword(s):

Supernova Remnants ◽

Supernova Remnant ◽

Narrow Band Imaging ◽

Large Magellanic Cloud ◽

Magellanic Cloud ◽

Main Body ◽

Found Objects ◽

Type Ia ◽

Optical Sample

ABSTRACT We present a new optical sample of three Supernova Remnants (SNRs) and 16 Supernova Remnant (SNR) candidates in the Large Magellanic Cloud (LMC). These objects were originally selected using deep H α, [S ii], and [O iii] narrow-band imaging. Most of the newly found objects are located in less dense regions, near or around the edges of the LMC’s main body. Together with previously suggested MCSNR J0541–6659, we confirm the SNR nature for two additional new objects: MCSNR J0522–6740 and MCSNR J0542–7104. Spectroscopic follow-up observations for 12 of the LMC objects confirm high [S ii]/H α emission-line ratios ranging from 0.5 to 1.1. We consider the candidate J0509–6402 to be a special example of the remnant of a possible type Ia Supernova (SN) which is situated some 2° (∼1.75 kpc) north from the main body of the LMC. We also find that the SNR candidates in our sample are significantly larger in size than the currently known LMC SNRs by a factor of ∼2. This could potentially imply that we are discovering a previously unknown but predicted, older class of large LMC SNRs that are only visible optically. Finally, we suggest that most of these LMC SNRs are residing in a very rarefied environment towards the end of their evolutionary span where they become less visible to radio and X-ray telescopes.

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NGC 2366 : An optical search for possible supernova remnants

New Astronomy ◽

10.1016/j.newast.2020.101492 ◽

2021 ◽

Vol 83 ◽

pp. 101492

Author(s):

E.N. Ercan ◽

E. AKTEKİN

Keyword(s):

Supernova Remnants

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Study of the extended radio emission of two supernova remnants and four planetary nebulae associated with MIPSGAL bubbles

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stu2081 ◽

2014 ◽

Vol 445 (4) ◽

pp. 4504-4514 ◽

Cited By ~ 8

Author(s):

A. Ingallinera ◽

C. Trigilio ◽

G. Umana ◽

P. Leto ◽

C. Agliozzo ◽

...

Keyword(s):

Radio Emission ◽

Supernova Remnants ◽

Planetary Nebulae ◽

Extended Radio

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An accreting < 105M⊙ black hole at the center of dwarf galaxy IC750

Proceedings of the International Astronomical Union ◽

10.1017/s1743921320003488 ◽

2019 ◽

Vol 15 (S356) ◽

pp. 376-376

Author(s):

Ingyin Zaw

Keyword(s):

Black Holes ◽

Black Hole ◽

Dwarf Galaxies ◽

Dwarf Galaxy ◽

Host Galaxy ◽

Scaling Relations ◽

Host Galaxies ◽

Seed Formation ◽

Maser Emission ◽

Water Masers

AbstractNuclear black holes in dwarf galaxies are important for understanding the low end of the supermassive black hole mass distribution and the black hole-host galaxy scaling relations. IC 750 is a rare system which hosts an AGN, found in ˜0.5% of dwarf galaxies, with circumnuclear 22 GHz water maser emission, found in ˜3–5% of Type 2 AGNs. Water masers, the only known tracer of warm, dense gas in the center parsec of AGNs resolvable in position and velocity, provide the most precise and accurate mass measurements of SMBHs outside the local group. We have mapped the maser emission in IC 750 and find that it traces a nearly edge-on warped disk, 0.2 pc in diameter. The central black hole has an upper limit mass of ˜1 × 105 M⊙ and a best fit mass of ˜8 × 104 M⊙, one to two orders of magnitude below what is expected from black hole-galaxy scaling relations. This has implications for models of black hole seed formation in the early universe, the growth of black holes, and their co-evolution with their host galaxies.

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