MG13 - Talk detail

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 Participant

Institution

Session

Accepted

Yes

Order

Time

Talk

Title

Abstract

Gravitational microlensing, in case of relevant finite source size effects, provides an unique tool for the study of stellar atmospheres through the enhancement of a characteristic polarization signal. Here, we consider a set of highly magnified events, both single and binary exoplanetary systems, observed towards the Galactic bulge and evaluate the expected polarization signal. To this purpose, we consider several polarization models which apply to different types of source stars: hot stars, main sequence and cool giants. We show that in some cases the polarization signal could be measurable by presently available polarimeters on the basis of the output from efficient alert systems.

Session

Accepted

No

Order

Time

Talk

Title

Abstract

The X--ray source 1RXS J180431.1$-$273932 has been proposed as a new member of the Symbiotic X--ray Binary (SyXB) class of systems, which are composed of a late-type giant which loses matter to an extremely compact object, most likely a neutron star. We present an optical campaign of imaging plus spectroscopy on selected candidate counterparts of this object; we also reanalyzed the available archival XMM-Newton X--ray data. We found that the optical counterpart is spectroscopically identified as a magnetic cataclysmic variable (CV), most likely of Intermediate Polar type, through the detection of prominent Balmer, He {\sc i}, He {\sc ii} and Bowen Blend emissions. We estimate a distance of 450 pc and a 0.2--10 keV X--ray luminosity of about 1.7x10^32 cgs for this system and a mass of 0.8 solar masses for the accreting white dwarf.

Session

Accepted

Yes

Order

Time

Talk

Title

Abstract

The optical brightness surface density of the globular cluster NGC 6388 suggests that it may harbor a central intermediate-mass black hole with mass of about 6x10^3 solar masses. Such a massive black hole is expected to be very active and, as a consequence, NGC 6388 was the target of several high-energy and radio observational campaigns in the X-ray and radio bands. We review the past observational campaigns which allowed to set limits on the BH mass. Recently, the interest in NGC 6388 raised again since a new high energy transient (IGRJ17361-4441) was observed by the INTEGRAL satellite. The source, close to the center of gravity of the globular cluster, became the target of follow-up observations conducted by the Chandra, Swift/XRT and RXTE observatories. Here, we concentrate on a set of observations conducted by the XMM-Newton satellite during two slews and address some conclusions about the possible IMBH nature of the source.

Session

Accepted

Yes

Order

Time

Talk

Title

Abstract

The X--ray source 1RXS J180431.1$-$273932 has been proposed as a new member of the Symbiotic X--ray Binary (SyXB) class of systems, which are composed of a late-type giant which loses matter to an extremely compact object, most likely a neutron star. We present an optical campaign of imaging plus spectroscopy on selected candidate counterparts of this object; we also re-analysed the available archival XMM-Newton X--ray data. We found that the optical counterpart is spectroscopically identified as a magnetic cataclysmic variable (CV), most likely of Intermediate Polar type, through the detection of prominent Balmer, He {\sc i}, He {\sc ii} and Bowen Blend emissions. We estimate a distance of 450 pc and a 0.2--10 keV X--ray luminosity of about 1.7x10^32 cgs for this system and a mass of 0.8 solar masses for the accreting white dwarf.

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