scholarly journals News from a Multi-Wavelength Monitoring Campaign on Mrk 421

2005 ◽  
Author(s):  
W. Cui
Keyword(s):  
Monitoring Campaign ◽  
Multi Wavelength ◽  
Wavelength Monitoring

scholarly journals X-ray and optical monitoring of the December 2017 outburst of the Be/X-ray binary AXJ0049.4–7323

2019 ◽  
Vol 621 ◽  
pp. A94 ◽  
Author(s):  
L. Ducci ◽  
C. Malacaria ◽  
P. Romano ◽  
L. Ji ◽  
E. Bozzo ◽  
...  
Keyword(s):  
Neutron Star ◽  
Optical Data ◽  
Sudden Increase ◽  
X Ray ◽  
Tidal Interactions ◽  
Near Ultraviolet ◽  
Peculiar Behaviour ◽  
Multi Wavelength ◽  
Wavelength Monitoring ◽  
Eccentricity Orbit

AXJ0049.4–7323 (SXP 756) is a Be/X-ray binary that shows an unusual and poorly understood optical variability that consists of periodic and bright optical outbursts, simultaneous with X-ray outbursts, characterised by a highly asymmetric profile. The periodicity of the outbursts is thought to correspond to the orbital period of the neutron star. To understand the peculiar behaviour shown by this source, we performed the first multi-wavelength monitoring campaign during the periastron passage of December 2017. The monitoring lasted for about 37 days and consisted of X-ray, near-ultraviolet, and optical data from the Neil Gehrels Swift Observatory, the optical I band from the OGLE survey, and spectroscopic observations of the Hα line performed with the 3.9 m Anglo-Australian Telescope. These observations revealed AXJ0049.4–7323 during an anomalous outburst having remarkably different properties compared to the previous ones. In the I band, it showed a longer rise timescale (∼60 days instead of 1–5 days) and a longer decay timescale. At the peak of the outburst, it showed a sudden increase in luminosity in the I band, corresponding to the onset of the X-ray outburst. The monitoring of the Hα emission line showed a fast and highly variable profile composed of three peaks with variable reciprocal brightness. To our knowledge, this is the second observation of a variable three-peak Hα profile of a Be/X-ray binary, after A0535+26. We interpreted these results as a circumstellar disc warped by tidal interactions with the neutron star in a high eccentricity orbit during its periastron passage. The fast jump in optical luminosity at the peak of the outburst and the previous asymmetric outbursts might be caused by the reprocessing of the X-ray photons in the circumstellar disc or the tidal displacement of a large amount of material from the circumstellar disc or the outer layers of the donor star during the periastron passage of the neutron star, which led to an increase in size of the region emitting in the I band. Further multi-wavelength observations are necessary to discriminate among the different scenarios proposed to explain the puzzling optical and X-ray properties of AXJ0049.4–7323.

scholarly journals Orbital Motion and Multi-Wavelength Monitoring of LkCa15 b

2013 ◽  
Vol 8 (S299) ◽  
pp. 199-203 ◽  
Author(s):  
Michael J. Ireland ◽  
Adam L. Kraus
Keyword(s):  
Infrared Imaging ◽  
Thermal Emission ◽  
Orbital Motion ◽  
Emission Model ◽  
Central Source ◽  
Multi Wavelength ◽  
Single Epoch ◽  
Wavelength Monitoring ◽  
Transition Disks

AbstractAs part of a deep multi-year non-redundant aperture mask infrared imaging campaign observing transition disks, we present multi-epoch monitoring of the resolved emission seen within the disk gap of LkCa 15. Orbital motion of both the central source and extended lobes as presented in Kraus and Ireland (2012) is clearly detected at the level of ~4 degrees/year (deprojected), in both K and L'-bands. Based on these data as well as single-epoch H and M bands epochs, we present two models for the central source - thermal emission as a planetary accretion signature and scattering. The thermal emission model is preferred.

scholarly journals JD6 - The Connection between Radio Properties and High Energy Emission in AGNs

2012 ◽  
Vol 10 (H16) ◽  
pp. 187-198
Author(s):  
Gabriele Giovannini ◽  
Teddy Cheung
Keyword(s):  
Gamma Ray ◽  
Galactic Nuclei ◽  
High Energy ◽  
Jet Physics ◽  
Spectral Energy ◽  
Essential Information ◽  
Multi Wavelength ◽  
Radio Band ◽  
High Energy Emission ◽  
Wavelength Monitoring

AbstractWhile observations in the radio band are providing essential information on the innermost structures of relativistic jets in active galactic nuclei (AGN), the recent detection byFermiof gamma-ray emission from many hundreds of blazars shows that the maximum jet power is emitted at high energies. Multi-wavelength monitoring observations further allow variability studies of the AGN spectral energy distributions over 13 orders of magnitude in frequency. The Joint Discussion offered the possibility for a comprehensive discussion of advances in the observational domain and stimulated theoretical discussion about our current understanding of jet physics.

scholarly journals The VLBA-BU-BLAZAR Multi-Wavelength Monitoring Program

Galaxies ◽  
2016 ◽  
Vol 4 (4) ◽  
pp. 47 ◽  
Author(s):  
Svetlana Jorstad ◽  
Alan Marscher
Keyword(s):  
Monitoring Program ◽  
Multi Wavelength ◽  
Wavelength Monitoring

scholarly journals Multi-wavelength monitoring of the microquasar GRS 1915+105

2009 ◽  
Author(s):  
Farid Rahoui ◽  
Sylvain Chaty ◽  
Jerome Rodriguez ◽  
Y. Fuchs ◽  
Igor Felix Mirabel
Keyword(s):  
Multi Wavelength ◽  
Wavelength Monitoring

scholarly journals Multi-wavelength monitoring of GRS 1915+105

1997 ◽  
Author(s):  
R. Bandyopadhyay ◽  
P. Martini ◽  
E. Gerard ◽  
P. A. Charles ◽  
R. M. Wagner ◽  
...  
Keyword(s):  
Multi Wavelength ◽  
Wavelength Monitoring

scholarly journals Multi-wavelength polarimetry and variability study of the M87 jet

2014 ◽  
Vol 10 (S313) ◽  
pp. 116-121
Author(s):  
Sayali S. Avachat ◽  
Eric S. Perlman ◽  
William B Sparks ◽  
Mihai Cara ◽  
Frazer N. Owen
Keyword(s):  
Magnetic Field ◽  
Angular Resolution ◽  
Polarized Light ◽  
Field Structure ◽  
Data Sets ◽  
Magnetic Field Structure ◽  
Multi Wavelength ◽  
Wavelength Monitoring ◽  
Variability Study ◽  
Better Than

AbstractWe present a high resolution polarimetry and variability study of the M87 jet using VLA and HST data taken during 2002 to 2008. Both data-sets have an angular resolution as high as 0.06”, which is 2-3 times better than previous observations. New morphological details are revealed in both the optical and radio, which can help to reveal the energetic and magnetic field structure of the jet. By comparing the data with previously published HST and VLA observations, we show that the jet's morphology in total and polarized light is changing significantly on timescales of ~1 decade. We compare the evolution of the inner jet (particularly the nucleus and knot HST-1), when our observations overlap with the multi-wavelength monitoring campaigns conducted with HST and Chandra. We use these data to comment on particle acceleration and main emission processes.

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