Two shell- and wing-shaped supernova remnants. Investigating the molecular environments around VRO 42.05.01 and G 350.0-2.0

Supernova remnants (SNRs) are profoundly affected by their ambient medium. We present carbon monoxide (CO) observations around two mixed morphology SNRs, VRO 42.05.01 and G 350.0-2.0, that look remarkably similar in continuum radio emission, showing what we refer to as a shell and wing shape. It has been proposed that the shell and wing shape is the result of environmental effects, in the form of a sharp density gradient or discontinuity. Our motivation for studying these two sources jointly is that if the dense molecular environment causes the development of these sources' shell and wing shape, then these two sources' environments must be similar. This is contrary to what we observe. In the case of VRO 42.05.01, we have found direct evidence of an interaction with its molecular environment, in the form of broadened $^{12}$CO line profiles, high $(J=2-1)$ to $(J=1-0)$ line ratios, and arc features in position-velocity space. We interpret some of these features to be associated with the SNR shock, and some of them to be due to the presence of a pre-supernova stellar wind. We have found no such features in the abundant molecular gas surrounding G 350.0-2.0. We have also made a spectral index map of G 350.0-2.0, and we see that the radio spectrum of G 350.0-2.0 steepens significantly at frequencies $<200$~MHz, much like that of VRO 42.05.01. In spite of their spectral and morphological similarities, these two sources look substantially different in their optical and infrared emission. The lack of large-scale correspondence between the radio continuum and the molecular material, as well as the differences in the excitation and morphological properties of the molecular gas surrounding both sources, lead us to conclude that the shell and wing morphology of these two sources is not due to interactions with a similar ambient molecular ISM.Comment: Accepted in Astronomy and Astrophysic

Two transiting hot Jupiters from the WASP survey : WASP-150b and WASP-176b

Funding: The research leading to these results has received funding from the European Research Council under the FP/2007-2013 ERC grant Agreement No. 336480 and from the ARC grant for Concerted Research Actions financed by the Wallonia-Brussels Federation. A.C.C. acknowledges support from the UK Science and Technology Facilities Council (STFC)consolidated grant No. ST/R000824/1.We report the discovery of two transiting exoplanets from the WASP survey, WASP-150b and WASP-176b. WASP-150b is an eccentric (e = 0.38) hot Jupiter on a 5.6 day orbit around a V = 12.03, F8 main-sequence host. The host star has a mass and radius of 1.4 M⊙ and 1.7 R⊙ respectively. WASP-150b has a mass and radius of 8.5 MJ and 1.1 RJ, leading to a large planetary bulk density of 6.4 ρJ. WASP-150b is found to be ~3 Gyr old, well below its circularization timescale, supporting the eccentric nature of the planet. WASP-176b is a hot Jupiter planet on a 3.9 day orbit around a V = 12.01, F9 sub-giant host. The host star has a mass and radius of 1.3 M⊙ and 1.9 R⊙. WASP-176b has a mass and radius of 0.86 MJ and 1.5 RJ, respectively, leading to a planetary bulk density of 0.23 ρJ.Publisher PDFPeer reviewe

Polarization and Spectral Energy Distribution in OJ 287 during the 2016/17 Outbursts

We report optical photometric and polarimetric observations of the blazar OJ 287 gathered during 2016/17. The high level of activity, noticed after the General Relativity Centenary flare, is argued to be part of the follow-up flares that exhibited high levels of polarization and originated in the primary black hole jet. We propose that the follow-up flares were induced as a result of accretion disk perturbations, traveling from the site of impact towards the primary SMBH. The timings inferred from our observations allowed us to estimate the propagation speed of these perturbations. Additionally, we make predictions for the future brightness of OJ 287.</p

Two transiting hot Jupiters from the WASP survey:WASP-150b and WASP-176b

We report the discovery of two transiting exoplanets from the WASP survey, WASP-150b and WASP-176b. WASP-150b is an eccentric (e = 0.38) hot Jupiter on a 5.6 day orbit around a V = 12.03, F8 main-sequence host. The host star has a mass and radius of 1.4 M⊙ and 1.7 R⊙ respectively. WASP-150b has a mass and radius of 8.5 MJ and 1.1 RJ, leading to a large planetary bulk density of 6.4 ρJ. WASP-150b is found to be ~3 Gyr old, well below its circularization timescale, supporting the eccentric nature of the planet. WASP-176b is a hot Jupiter planet on a 3.9 day orbit around a V = 12.01, F9 sub-giant host. The host star has a mass and radius of 1.3 M⊙ and 1.9 R⊙. WASP-176b has a mass and radius of 0.86 MJ and 1.5 RJ, respectively, leading to a planetary bulk density of 0.23 ρJ