*IoA Seminar 2015 / 平成27年度/2015年度・東京大学・天文学教育研究センター・談話会 [#r718054a]
#contents
* 次回以降の談話会 [#x853b099]
** No. 262: 2015/4/9 (Thu) 15:30-16:30 [#o40eeb27]
*** Speaker: Linda Tacconi (MPE Garching) [#ia238304]
*** Title: The Evolution of Molecular Gas and Star Formation from the Peak Epoch of Galaxy Formation to the Present [#pc5da7b2]
Comprehensive and systematic studies of the molecular content of galaxies during the epochs that are associated with the peak (z~1-2), and subsequent winding down (z<1) of star formation in the Universe are enabling us to illustrate the important role that cold gas, , the fuel for star formation, has played in the assembly of galaxies across cosmic time. Surveys, including COLDGASS and PHIBSS1&2, already provide robust molecular gas detections in hundreds of normal, star forming galaxies, from redshifts 0-2.5. In this talk, we focus on results from PHIBSS, comprising two IRAM Large Programs, where we are we have are mapping the CO J=3-2 or J-2-1 line emission in ~200 such galaxies from z=0.5-2.5; we find that galaxies at these epochs are very gas rich, relative to their star-forming counterparts in the local Universe. We discuss scaling relations for massive star forming galaxies that we derive from these data, and the impact of all of these new observations on our understanding of galaxy evolution in the early Universe.
** No. 263: 2015/4/16 (Thu) 15:30-16:30 [#b9dbd50b]
*** Speaker: Masao Saito (Nobeyama Radio Observatory, NAOJ) [#kda642a6]
*** Title: Starformation Project: SOLA [#x2ce86f2]
The multi-national SOLA (Soul of Lupus with ALMA) consortium has
initiated a very large program to conduct comprehensive studies of the
Lupus Molecular Clouds and their star formation processes. The long-term
goal is to exploit ALMA and other growing observational capabilities in
the southern hemisphere to establish the Lupus region as a prototypical
low-mass star forming region on a par with, for example, the Taurus
clouds in the northern sky. In this talk, I present how I started the
SOLA project and how I managed the team together with the latest status.
** No. 264: 2015/5/14 (Thu) 15:30-16:30 [#b9dbd50b]
*** Speaker: 秋山和徳 (水沢VLBI観測所, NAOJ) [#n8903d33]
*** Title: TBA [#m25fa7f3]
** No. 265: 2015/5/21 (Thu) 15:30-16:30 [#b9dbd50b]
*** Speaker: Toshio FUKUSHIMA (NAOJ) [#ba4f158e]
*** Title: Precise and fast computation of generalized Fermi-Dirac integral by parameter polynomial approximation [#s3f0e02b]
The generalized Fermi-Dirac integral, $F_k(\eta,\beta)$, is approximated
by a group of polynomials of $\beta$ as $F_k(\eta,\beta) \approx
\sum_{j=0}^J g_j \beta^j F_{k+j} (\eta)$ where $J=1(1)10$. Here
$F_k(\eta)$ is the Fermi-Dirac integral of order $k$ while $g_j$ are
the numerical coefficients of the single and double precision minimax
polynomial approximations of the generalization factor as $\sqrt{1+x/2}
\approx \sum_{j=0}^J g_j x^j$. If $\beta$ is not so large, an appropriate
combination of these approximations computes $F_k(\eta,\beta)$ precisely
when $\eta$ is too small to apply the optimally truncated Sommerfeld
expansion (Fukushima, 2014, Appl. Math. Comp., 234, 417). For example,
a degree 8 single precision polynomial approximation guarantees the 24 bit
accuracy of $F_k(\eta,\beta)$ of the orders, $k=-1/2(1)5/2$, when
$-\infty < \eta \le 8.92$ and $\beta \le 0.2113$. Also, a degree 7 double
precision polynomial approximation assures the 15 digit accuracy of
$F_k(\eta,\beta)$ of the same orders when $-\infty < \eta \le 29.33$
and $0 \le \beta \le 3.999 \times 10^{-3}$. Thanks to the piecewise
minimax rational approximations of $F_k(\eta)$ (Fukushima, 2015, Appl.
Math. Comp., 259, 708), the averaged CPU time of the new method is
only 0.9--1.4 times that of the evaluation of the integrand of
$F_k(\eta,\beta)$. Since most of $F_k(\eta)$ are commonly used in
the approximation of $F_k(\eta,\beta)$ of multiple contiguous orders,
the simultaneous computation of $F_k(\eta,\beta)$ of these orders is
further accelerated by the factor 2--4. As a result, the new method
runs 70-450 times faster than the direct numerical integration in
practical applications requiring $F_k(\eta, \beta)$.
** 趣旨 [#aee2547a]
東京大学・天文学教育研究センターでは2003年4月から, [[院生コロキウム:http://www.ioa.s.u-tokyo.ac.jp/colloquium/wiki/]]に引き続き, 談話会を開いています.
第一線で活躍されている研究者の方々を講師にお招きし, 最先端の研究成果をお話しいただきます.
講師の方には, 大学院生の参加者のことも考慮し, レビュー的な側面も含めた上で, ご自身の研究紹介をお願いしています.
**日時 [#obf728fc]
-木曜日
-15:30-16:30
**場所 [#u1b71b6f]
-天文センター講義室
**標準タイムテーブル [#ee9b79df]
|13:30-14:30|[[院生コロキウム:http://www.ioa.s.u-tokyo.ac.jp/colloquium/wiki/]]|講義室|
|15:30-16:30|談話会|講義室|
|16:30-|お茶の時間|講義室横のお茶部屋~講師の方を交えて~|
**世話人 [#d1aed128]
-石井峻: sishii _at_ ioa.s.u-tokyo.ac.jp (_at_を@に置き換えてください)
-田中培生: mtanaka _at_ ioa.s.u-tokyo.ac.jp (_at_を@に置き換えてください)
-河野孝太郎: kkohno _at_ ioa.s.u-tokyo.ac.jp (_at_を@に置き換えてください)
** Schedule [#re3c4f45]
|BGCOLOR(cyan):#|BGCOLOR(cyan): Date|BGCOLOR(cyan):Speakers|BGCOLOR(cyan):Title|
|262|2015/4/09(Thu)|Linda Tacconi (MPE Garching)|The Evolution of Molecular Gas and Star Formation from the Peak Epoch of Galaxy Formation to the Present|
|263|2015/4/16(Thu)|齋藤正雄 (NRO, NAOJ)|Starformation Project: SOLA|
|264|2015/5/14(Thu)|秋山和徳 (水沢VLBI観測所, NAOJ)|(TBA)|
|265|2015/5/21(Thu)|Toshio FUKUSHIMA (NAOJ)|Precise and fast computation of generalized Fermi-Dirac integral by parameter polynomial approximation|
**終了した談話会(2015年度) [#hd234e7c]
詳細はこちら: [[平成27 (2015) 年度談話会]]
|BGCOLOR(cyan):#|BGCOLOR(cyan):日付|BGCOLOR(cyan):講演者 (所属)|BGCOLOR(cyan):タイトル|
**これまでの談話会 [#jd1b377c]
-[[平成27 (2015) 年度談話会]]
-[[平成26 (2014) 年度談話会]]
-[[平成25 (2013) 年度談話会]]
-[[平成24 (2012) 年度談話会]]
-[[平成23 (2011) 年度談話会]]
-[[平成22 (2010) 年度談話会:http://www.ioa.s.u-tokyo.ac.jp/danwakai//past/danwakai_H22.html]]
-[[平成21 (2009) 年度談話会:http://www.ioa.s.u-tokyo.ac.jp/danwakai//past/danwakai_H21.html]]
-[[平成20 (2008) 年度談話会:http://www.ioa.s.u-tokyo.ac.jp/danwakai//past/danwakai_H20.html]]
-[[平成19 (2007) 年度談話会:http://www.ioa.s.u-tokyo.ac.jp/danwakai//past/danwakai_H19.html]]
-[[平成18 (2006) 年度談話会:http://www.ioa.s.u-tokyo.ac.jp/danwakai//past/danwakai_H18.html]]
-[[平成17 (2005) 年度談話会:http://www.ioa.s.u-tokyo.ac.jp/danwakai//past/danwakai_H17.html]]
-[[平成16 (2004) 年度談話会:http://www.ioa.s.u-tokyo.ac.jp/danwakai//past/danwakai_H16.html]]
-[[平成15 (2003) 年度談話会:http://www.ioa.s.u-tokyo.ac.jp/danwakai//past/danwakai_H15.html]]
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