Talk detail

Participant	ADEGOKE, OLUWASHINA
Institution	INDIAN INSTITUTE OF SCIENCE - BANGALORE - BANGALORE - KARNATAKA - India

Session	AC3	Accepted		Order	Time
Talk	Oral abstract	Title	CORRELATING NON-LINEAR PROPERTIES OF COMPACT OBJECTS WITH SPECTRAL STATES: GRS 1915+105 A CASE STUDY
Coauthors
Abstract	As already reported by earlier works, the black hole binary GRS 1915+105 and a few other X-ray binaries exhibit different non-linear features depending on variations in their temporal classes. Sometimes they show low correlation/fractal dimension, but in other classes or intervals of time they exhibit stochastic nature. The question then arises: What is the connection of non-linearity to the underlying spectral properties of the flows when the non-linear properties are related to the associated transport mechanisms describing the geometry of the flow. This work is aimed at addressing the question. By studying the spectral and non-linear timing properties GRS 1915+105 in all its known temporal classes, we attempt to diagnose the underlying accretion modes in this source in terms of known accretion classes, namely: Keplerian Disc, Slim Disc, Advection Dominated Accretion Flow and General Advective Accretion Flow.
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Session	BH2	Accepted		Order	Time
Talk	Poster abstract	Title	OBSERVATIONS OF THE SEYFERT 1 AGN Zw 229.015 VIS-A-VIS THEORETICAL PREDICTIONS
Coauthors
Abstract	By using the archival XMM-Newton and Swift data of the nearby Seyfert 1 AGN Zw 229.015, we study both the spectral and temporal properties of the central black holes in remarkable detail. The energy spectra show soft excess emission which is consistent with both inverse comptonization from a warm corona and relativistically blurred reflection close to the black holes. From the time lag estimate between the soft and the hard X-rays, we compute the size of the corona system to be about 20Rg. On the other hand, on longer time-scale using the Swift archival data of Zw 229.015, a time delay between the UV and the X-ray emission could not be established with certainty although apparently the source appears to be brighter in UV when softer in X-rays.
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Session	AC1	Accepted		Order	Time
Talk	Poster abstract	Title	PROBING THE UV/X-RAY PROPERTIES OF THE NLS1 AGN MRK 493: THEORY vs. OBSERVATION
Coauthors
Abstract	We analyse the archival XMM-Newton observation of the Narrow-line Seyfert 1 active galactic nucleus Mrk 493 in the UV and the X-ray energy band 0.3 − 10keV. We use the fractional variability amplitude Fvar to quantify the variability seen in the source’s lightcurves. While the UV emission variability of Mrk 493 is comparable to that seen in several other Seyfert 1 AGNs (Fvar ∼ 3.1 ± 0.2), its X-ray variability (Fvar ∼ 20.7 ± 0.4) is atleast a factor of 2 less than what is estimated for several Seyfert 1 AGNs. Cross-correlation analysis show that the UV emission lead the X-ray emission by about 5-10 ks. We show that the UV lead is consistent with theoretical predictions of the time taken by the UV photons to travel from the location of their origin in the accretion disc to the hot corona and the time required for repeated inverse Compton scattering converting the UV photons into X-ray photons.
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