این هفته شاهد دفاع خانم حلیمه السادات میرآقایی جعفری از رساله دکتریشان خواهیم بود. ایشان رساله خود را با راهنمایی دکتر راهوار و دکتر خسروشاهی انجام داده‌اند. عنوان و چکیدهٔ سمینار ایشان به شرح زیر است:

گرمایش محیط میان کهکشانی در گروه های کهکشانی فسیل

 (IGM Heating in Fossil Galaxy Groups)

Abstract:  Fossil galaxy groups, famed to have undisturbed inter-galactic gas due to lack of recent groupscale mergers, are energetically and morphologically ideal environments to study the IGMheating. In this article, we study the role of active galactic nuclei in heating the IGM in asample of five fossil galaxy groups by employing their GMRT observations at 610 MHz and1.4 GHz. We find that only two of the dominant galaxies in fossil groups are associated withthe radio lobes. We evaluate the PdV work of the radio lobes and their corresponding heatingpower and compare to the X-ray emission loss within cooling radius. Our results show thatthe power due to mechanical heating is not sufficiently high to suppress the cooling. We alsoconsidered shock and vortex heating and conduction as alternative heating sources. The 1.4GHz and 610 MHz radio luminosities of fossil groups are compared to a sample of normalgalaxy groups for the same BGGs stellar mass and total group stellar mass quantified usingthe K-band luminosity. It appears that the fossil BGGs are under luminous at 1.4 GHz and610 MHz for a given BGG stellar mass, luminosity, in comparison to a general population ofthe groups. We also explore how the bolometric radio luminosity of fossil sample dependson clusters and groups characteristics. We find that fossil groups follow the strong cool coreclusters, from HILFUGCS sample, as far as the large scale characteristics of the groups aretaken into account, consistent with the relaxed and virialized nature of fossil galaxy groups.

این سمینار در روز یکشنبه ۱۸ آبان ماه ۱۳۹۳، ساعت ۱۵ در کلاس فیزیک ۴ در طبقهٔ اول دانشکدهٔ فیزیک برگزار خواهد شد.