Powerful bursts of water masers towards G25.65+1.05

Volvach, L. N.; Volvach, A. E.; Ларионов, М. Г.; MacLeod, G. C.; Heever, S. P. van den; Wolak, P.; Олеч, M.

doi:10.1093/mnrasl/sly193

Cited by 30 publications

(24 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Significant water maser flaring activity, brighter than 10 kJy, has been reported previously by Hirota et al (2014) for Orion KL, by Volvach et al (2019b) for G25.65+1.05, and by Volvach et al (2019a) for W49N. The authors reported a relationship between line width and flux density that is similar to what we observed here.…”

Section: Discussionsupporting

confidence: 92%

Flaring water masers associated with W49N

Volvach

Ларионов

et al. 2019

A&A

View full text Add to dashboard Cite

Aims. We present our monitoring observations and analysis of water masers associated with W49N taken in 2017 and 2018. A significant flare occurred during these observations. Methods. We used ground-based radio telescopes in Simeiz (RT-22), Torun (RT-32), Medicina (RT-32), Effelsberg (RT-100) with broadband spectrometers. Observational data were collected and processed automatically. Results. We report a powerful flare of the v = +6 km s−1 water maser feature; it increased in over ten months to S1.3 cm = 84 kJy in 2017 December, then decayed to the pre-flare quiescent value of S1.3 cm = 8.7 kJy in 2018 August. We infer that this flaring feature is unsaturated based on the relationship between line width and flux density.

show abstract

Section: Discussionsupporting

confidence: 92%

Flaring water masers associated with W49N

Volvach

Ларионов

et al. 2019

A&A

View full text Add to dashboard Cite

show abstract

“…The linear flux dependence of the square of the line width in the minus first power suggests that the maser is in an unsaturated regime. Similar results were also obtained for the giant flares in Orion KL and IRAS 18316-0602 (Omodaka et al 1999;Shimoikura et al 2005;Volvach et al 2019a). In all cases, it was concluded that the masers are in an unsaturated state up to the maximum flare amplitude.…”

Section: Monitoring Of the Spectral Flux Density In W49n In The High-supporting

confidence: 83%

A Water-Vapor Maser Flare in a High-Velocity Line toward W49N

Volvach

Ларионов

et al. 2019

Astron. Lett.

View full text Add to dashboard Cite

Powerful flares in Galactic kilomasers are closely associated with regions of intense star formation. They contribute to the elucidation of physical processes occurring in these structures. We have recorded a superpowerful flare in the high-velocity −81 km s −1 line in the Galactic maser source W49N. As a result of our monitoring at the RT-22 (Simeiz), RT-32 (Torun), RT-100 (Effelsberg), and RT-32 (Medicina) radio telescopes in the period from September 2017 to November 2018, we have obtained the shape of the spectral flux density variations in the source with time. At the peak the flux density reached P ≈ 5 × 10 4 Jy. The flare has a double pattern and different durations of its components. The pattern of spectral flux density variations for the first flare with a considerably shorter duration is apparently related to a sharp increase in the density of the medium and the photon flux and to a significant rise in the temperature to hundreds of kelvins. We propose a mechanism of primary energy release related to the existence of close massive multiple systems in star-forming regions. A powerful gravitational perturbation at the system's periastron can lead to a partial ejection of the envelope of the central massive star in a direction close to the major axis of the ellipse of the companion's orbit. This explains the significant asymmetry of high-velocity lines in W49N. The ejected envelope is an energy source more significant than the stellar wind and can explain the giant flares in the object. Further comprehensive studies in this direction, including monitoring VLBI studies, are needed to confirm this assumption.

show abstract

“…The flux density of the bursting feature is seen to vary by several hundreds of Jy during the observation campaign -indeed G25.65+1.05 is known to be extremely variable [5]. It can also be noted from the spectrum in Figure 2 that significant flux variation is seen exclusively in the bursting maser spectral feature; the low-flux spectral features remain constant during the campaign.…”

Section: Discussionmentioning

confidence: 82%

“…Burst activity of > 18, 000 Jy was reported by the single-dish Maser Monitoring Organisation (M2O) on the 7-8th of September, after which the maser rose to 65,000 Jy in late September [7,5]. Target of opportunity observations of the 22 GHz water maser in G25.65+1.05 were requested to the European VLBI network (EVN), the KVN and VERA Array (KaVA) and the Very Long Baseline Array (VLBA) and observations were conducted on the 2nd, 11th and 28th of October 2017, respectively.…”

Section: Observationsmentioning

confidence: 99%

See 1 more Smart Citation

Multi-epoch VLBI of a double maser super burst

Burns¹,

Bayandina²,

Orosz³

et al. 2019

Proceedings of 14th European VLBI Network Symposium &Amp; Users Meeting — PoS(EVN2018)

View full text Add to dashboard Cite

In a rare and spectacular display, two well-known massive star forming regions, W49N and G25.65+1.05, recently underwent maser 'super burst' -their fluxes suddenly increasing above 30,000 and 18,000 Jy, respectively, reaching several orders of magnitude above their usual values. In quick-response, ToO observations with the EVN, VLBA and KaVA were obtained constituting a 4 week campaign -producing a high-cadence multi-epoch VLBI investigation of the maser emission. The combination of high-resolution, polarisation and flux monitoring during the burst provides one of the best accounts, to date, of the maser super burst phenomenon, aiding their use as astrophysical tools. These proceedings contain the preliminary results of our campaign.

show abstract

Powerful bursts of water masers towards G25.65+1.05

Cited by 30 publications

References 14 publications

Flaring water masers associated with W49N

Flaring water masers associated with W49N

A Water-Vapor Maser Flare in a High-Velocity Line toward W49N

Multi-epoch VLBI of a double maser super burst

Contact Info

Product

Resources

About