3 research outputs found
Analysis of the interstellar matter at the periphery of the supershell surrounding the CYG OB1 association in 2.12 micron molecular hydrogen line
We present observations of the vdB 130 cluster vicinity in a narrow-band
filter centered at a m molecular hydrogen line performed at the
Caucasus Mountain Observatory of the Lomonosov Moscow State University. The
observations reveal an H emission shell around vdB 130, coincident with a
bright infrared shell, visible in all \textit{Spitzer} bands. Also, numerous
H emission features are detected around infrared Blobs E and W and in the
vicinity of a protocluster located to the east of the shell, in a tail of a
cometary molecular cloud. H emission in the vicinity of the vdB~130 cluster
is mostly generated in well-developed \HII\ regions and is of fluorescent
nature. In the protocluster area, isolated spots are observed, where H
emission is collisionally excited and is probably related to shocks in
protostellar outflows. Obtained results are discussed in the context of
possible sequential star formation in the vicinity of the vdB 130 cluster,
triggered by the interaction of the expanding supershell surrounding the Cyg
OB1 association with the molecular cloud and an associated molecular filament.Comment: Accepted by Astrophysical Bulleti
Multiwavelength monitoring and reverberation mapping of a changing look event in the Seyfert galaxy NGC 3516
We present the results of photometric and spectroscopic monitoring campaigns of the changing look AGN NGC 3516 carried out in 2018 to 2020 covering the wavelength range from the X-ray to the optical. The facilities included the telescopes of the CMO SAI MSU, the 2.3-m WIRO telescope, and the XRT and UVOT of Swift. We found that NGC 3516 brightened to a high state and could be classified as Sy1.5 during the late spring of 2020. We have measured time delays in the responses of the Balmer and He ii λ4686 lines to continuum variations. In the case of the best-characterized broad H β line, the delay to continuum variability is about 17 d in the blue wing and is clearly shorter, 9 d, in the red, which is suggestive of inflow. As the broad lines strengthened, the blue side came to dominate the Balmer lines, resulting in very asymmetric profiles with blueshifted peaks during this high state. During the outburst the X-ray flux reached its maximum on 2020 April 1 and it was the highest value ever observed for NGC 3516 by the Swift observatory. The X-ray hard photon index became softer, ∼1.8 in the maximum on 2020 April 21 compared to the mean ∼0.7 during earlier epochs before 2020. We have found that the UV and optical variations correlated well (with a small time delay of 1-2 d) with the X-ray until the beginning of 2020 April, but later, until the end of 2020 June, these variations were not correlated. We suggest that this fact may be a consequence of partial obscuration by Compton-thick clouds crossing the line of sight