Related papers: VLBI Observations of SN 2008D
The Swift Gamma-Ray Burst Explorer, launched on 2004 November 20, is a multiwavelength, autonomous, rapid-slewing observatory for gamma-ray burst (GRB) astronomy. On 2004 December 23, during the activation phase of the mission, the Swift…
Flares in radio-loud AGN are thought to be associated with the injection of fresh plasma into the compact jet base. Such flares are usually strongest and appear earlier at shorter radio wavelengths. Hence, VLBI at mm-wavelengths is best…
We present optical photometry and spectroscopy from about a week after explosion to $\sim$272 d of an atypical Type IIP supernova, SN 2015ba, which exploded in the edge-on galaxy IC 1029. SN 2015ba is a luminous event with an absolute…
Given the possible repetitive nature of fast radio bursts (FRBs), their cosmological origin, and their high occurrence, detection of strongly lensed sources due to intervening galaxy lenses is possible with forthcoming radio surveys. We…
Using millimeter-very long baseline interferometry (VLBI) observations of the BL Lac object S5 0716+714 from August 2008 to September 2013, we investigate variations in the core flux density and orientation of the sub-parsec scale jet i.e.…
We present 121 days of multi-band (\Bband, \gband, \rband, \iband) optical photometry of the Type Ia supernova SN 2025bvm, obtained with the COLIBRI telescope at OAN-SPM. The light curves show a photometric decline of $\Delta m_{15}(B) =…
We present results of long-term high-frequency VLBI monitoring of the relativistic jet in 3C279, consisting of 18 epochs at 22 GHz from 1991 to 1997 and 10 epochs at 43 GHz from 1995 to 1997. Three major results of this study are: apparent…
We present the results from an Hubble Space Telescope/ACS search for supernovae associated with X-ray flashes 020903, 040701, 040812 and 040916. We find strong evidence that XRF 020903 (z=0.25) was associated with a SN 1998bw-like supernova…
The nearby galaxy NGC 300 is hosting two luminous transient supersoft X-ray sources with bolometric luminosities above 3x10^38 erg/s, assuming simple black-body spectra with temperatures around 60-70 eV. For one of these, SSS1, a periodic…
We report on new Very Long Baseline Interferometry radio measurements of supernova 2014C in the spiral galaxy NGC 7331, made with the European VLBI Network ~5 yr after the explosion, as well as on flux density measurements made with the…
We present the results of a program to monitor the structure of the radio emission in 42 $\gamma$-ray bright blazars (31 quasars and 11 BL Lac objects) with the VLBA at 43, 22, and occasionally 15 and 8.4 GHz, over the period from November…
We present a high-frequency very long baseline interferometry (VLBI) kinematical study of the BL Lac object S5 0716+714 over the time period of September 2008 to October 2010. The aim of the study is to investigate the relation of the jet…
We report on the spectroscopic detection of supernova SN 2010ma associated with the long gamma-ray burst GRB 101219B. We observed the optical counterpart of the GRB on three nights with the X-shooter spectrograph at the VLT. From weak…
We present 5 GHz global VLBI observations of the two Fanaroff Riley Type I radio galaxies B2 0836+29 and 3C465 (2335+26). For 3C465 we present also 1.7 GHz and 8.4 GHz global VLBI data. In addition VLA observations were used to obtain…
We present visual-wavelength photometry and spectroscopy of supernova SN2008S. Based on the low peak luminosity for a SN of M_R = -13.9 mag, photometric and spectral evolution unlike that of low-luminosity SNe, a late-time decline rate…
We present near-IR observations of the 2010 outburst of U Sco. JHK photometry is presented on ten consecutive days starting from 0.59 days after outburst. Such photometry can gainfully be integrated into a larger database of other…
There is still a limited number of high-redshift ($z>3$) active galactic nuclei (AGN) whose jet kinematics have been studied with very long baseline interferometry (VLBI). Without a dedicated proper motion survey, regularly conducted…
Luminous X-ray outbursts with variability amplitudes as high as ~1000 have been detected from a small number of galactic nuclei. These events are likely associated with transient fueling of nuclear supermassive black holes. In this paper,…
We report a serendipitous detection of rapid, large amplitude flux density variations in the highly core-dominated, flat-spectrum radio quasar 1156+295 during an observing session at the Very Long Baseline Array (VLBA). The source was…
We report on our early photometric and spectroscopic observations of the extremely luminous Type II supernova (SN) 2008es. With an observed peak optical magnitude of m_V = 17.8 and at a redshift z = 0.213, SN 2008es had a peak absolute…