سمینار این هفته را <فرهنگ حبیبی> برگزار خواهند کرد. عنوان و چکیدهٔ سمینار ایشان به شرح زیر است:
Title:
Searching for Galactic Hidden Gas through interstellar scintillation.
Abstract:
Through my talk, I will shortly explain the scintillation effect produced
by molecular turbulent mediums. By showing the results obtained from the
simulations, the connection between the observables and turbulence
characteristics are derived. At last, I describe how we put limit on
turbulence of the hypothesized unseen gaseous matter of the Galactic
halo from the light curves of the SMC stars.
این سمینار در روز <یکشنبه> <9 آبان 1389> در ساعت <15> درامفی تئاتردانشکدهٔ فیزیک برگزار خواهد شد.
سمینار این هفته را <شانت باغرام> برگزار خواهند کرد. عنوان و چکیدهٔ سمینار ایشان به شرح زیر است:
Title:
Dark Matter Structures from astrophysical probes to Cosmological implications.
Abstract:
In this talk, I will review the most important aspects in Dark matter structures in the Universe and the
corresponding models in Linear and Nonlinear regimes which describes the matter distribution and its statistics.
Then a new probe for dark matter substructures detection with pulsars timing will be described.
Finally the importance and the role of Dark matter distribution statistics introduced as a promising cosmological probe as
distinguishing tool for cosmological models proposed for the acceleration of the Universe.
این سمینار در روز <یکشنبه> <2 آبان 1389> در ساعت <15> درامفی تئاتردانشکدهٔ فیزیک برگزار خواهد شد.
سمینار این هفته را <شانت باغرام> برگزار خواهند کرد. عنوان و چکیدهٔ سمینار ایشان به شرح زیر است:
Title:
Dark Matter Structures from astrophysical probes to Cosmological implications
Abstract:
In this talk, I will review the most important aspects in Dark matter structures in the Universe and the
corresponding models in Linear and Nonlinear regimes which describes the matter distribution and its statistics.
Then a new probe for dark matter substructures detection with pulsars timing will be described.
Finally the importance and the role of Dark matter distribution statistics introduced as a promising cosmological probe as
distinguishing tool for cosmological models proposed for the acceleration of the Universe
.این سمینار در روز <یکشنبه> <25 مهر ۱۳۸۹> در ساعت <15> در امفی تئاتر دانشکدهٔ فیزیک برگزار خواهد شد.
سمینار این هفته را <احمد مهرابی> برگزار خواهند کرد. عنوان و چکیدهٔ سمینار ایشان به شرح زیر است:
Title:
A review on papar “Frequency of Solar-Like Systems and of Ice and Gas Giants Beyond the Snow Line from High-Magnification Microlensing Events in 2005-2008.
We present the first measurement of planet frequency beyond the “snow line” for planet/star mass-ratios[-4.5<log q<-2]: d^2 N/dlog q/dlog s=(0.36+-0.15)/dex^2 at mean mass ratio q=5e-4, and consistent with being flat in log projected separation, s. Our result is based on a sample of 6 planets detected from intensive follow-up of high-mag (A>200) microlensing events during 2005-8. The sample host stars have typical mass M_host 0.5 Msun, and detection is sensitive to planets over a range of projected separations (R_E/s_max,R_E*s_max), where R_E 3.5 AU sqrt(M_host/Msun) is the Einstein radius and s_max (q/5e-5)^{2/3}, corresponding to deprojected separations ~3 times the “snow line”. Though frenetic, the observations constitute a “controlled experiment”, which permits measurement of absolute planet frequency. High-mag events are rare, but the high-mag channel is efficient: half of high-mag events were successfully monitored and half of these yielded planet detections. The planet frequency derived from microlensing is a factor 7 larger than from RV studies at factor ~25 smaller separations [2<P<2000 days]. However, this difference is basically consistent with the gradient derived from RV studies (when extrapolated well beyond the separations from which it is measured). This suggests a universal separation distribution across 2 dex in semi-major axis, 2 dex in mass ratio, and 0.3 dex in host mass. Finally, if all planetary systems were “analogs” of the Solar System, our sample would have yielded 18.2 planets (11.4 “Jupiters”, 6.4 “Saturns”, 0.3 “Uranuses”, 0.2 “Neptunes”) including 6.1 systems with 2 or more planet detections. This compares to 6 planets including one 2-planet system in the actual sample, implying a first estimate of 1/6 for the frequency of solar-like systems.
این سمینار در روز <یکشنبه> <18مهر ۱۳۸9> در ساعت <15> درامفی تئاتردانشکدهٔ فیزیک برگزار خواهد شد.
سمینار این هفته را <آقای احمد مهرابی> برگزار خواهند کرد. عنوان و چکیدهٔ سمینار ایشان به شرح زیر است:
Title:
َA review on papar “Frequency of Solar-Like Systems and of Ice and Gas Giants Beyond the Snow Line from High-Magnification Microlensing Events in 2005-2008.
We present the first measurement of planet frequency beyond the “snow line” for planet/star mass-ratios[-4.5<log q<-2]: d^2 N/dlog q/dlog s=(0.36+-0.15)/dex^2 at mean mass ratio q=5e-4, and consistent with being flat in log projected separation, s. Our result is based on a sample of 6 planets detected from intensive follow-up of high-mag (A>200) microlensing events during 2005-8. The sample host stars have typical mass M_host 0.5 Msun, and detection is sensitive to planets over a range of projected separations (R_E/s_max,R_E*s_max), where R_E 3.5 AU sqrt(M_host/Msun) is the Einstein radius and s_max (q/5e-5)^{2/3}, corresponding to deprojected separations ~3 times the “snow line”. Though frenetic, the observations constitute a “controlled experiment”, which permits measurement of absolute planet frequency. High-mag events are rare, but the high-mag channel is efficient: half of high-mag events were successfully monitored and half of these yielded planet detections. The planet frequency derived from microlensing is a factor 7 larger than from RV studies at factor ~25 smaller separations [2<P<2000 days]. However, this difference is basically consistent with the gradient derived from RV studies (when extrapolated well beyond the separations from which it is measured). This suggests a universal separation distribution across 2 dex in semi-major axis, 2 dex in mass ratio, and 0.3 dex in host mass. Finally, if all planetary systems were “analogs” of the Solar System, our sample would have yielded 18.2 planets (11.4 “Jupiters”, 6.4 “Saturns”, 0.3 “Uranuses”, 0.2 “Neptunes”) including 6.1 systems with 2 or more planet detections. This compares to 6 planets including one 2-planet system in the actual sample, implying a first estimate of 1/6 for the frequency of solar-like systems.
این سمینار در روز <یکشنبه> <11 مهر 1389> در ساعت <15> در امفی تئاتر دانشکدهٔ فیزیک برگزار خواهد شد.
سمینار این هفته را <آقای رازبین> برگزار خواهند کرد. عنوان و چکیدهٔ سمینار ایشان به شرح زیر است:
Title:
general relativistic mass and velocity for LTB structure.
Abstract:
This presenttion is about first steps of my M.sc project under supervision of profesor Reza Mansouri and
it deal with calculation of velocity and mass profile for a LTB structure.this will lead to direct camparition of classical profile
and general relativistic profile.I will disscus about clear diffinition of problem and then I will show some calculation about
angular velocity and I will finish presentation with some quastion
این سمینار در روز <یکشنبه> <4 مهر1389> در ساعت <15:00> در اتاق ۵۱۷ (اتاق قطب علمی) در طبقهٔ پنجم دانشکدهٔ فیزیک برگزار خواهد شد.
کنفرانس In the Spirit of Lyot 2010 در باره رصد مستقیم سیارات فراخورشیدی و دیسک های ستاره ای از 25 الی 29 اکتبر در پاریس برگزار می شود . برای اطلاعات بیشتر به وبگاه این کنفرانس مراجعه کنید.
از این پس سعی خواهیم کرد ، اطلاعات و اعلانات مربوط به کنفرانس های مربوط به کیهانشناسی و اختر فیزیک را در وبگاه گروه قرار دهیم. لطفا در به روزرسانی اعلام کنفرانس ها همراهی کنید .
