TALKS.
Wednesday, October 15 2014, 11 am
Speaker:
Saeko Hayashi (Subaru Telescope)
Title:
TBA
Abstract:
TBA
Wednesday, August 27 2014, 11 am
Speaker:
Yutaka Hayano (Subaru Telescope)
Title:
An application of adaptive optics technique to bio-imaging
Abstract:
We have been investigating to apply the AO technique to bioimaging of the living cells of a moss, Physcomitrella patens by microscope since 2011. Fluorescent beads or proteins, as well as a spot of auto fluorescence generated by focused laser beam on to a chloroplast are used as an AO guide star to compensate wavefront error caused by biological structures, which have different refractive index. Additionally, preliminary experiments of compensating a wavefront error of fluorescent beads behind a Drosophila embryo and Oryzias (Medaka) are introduced.
HOT
Wednesday, August 6 2014, 11 am
Speaker:
Josh Walawender (Subaru Telescope)
Title:
SciPy for Astronomers
Abstract:
I will give a whirlwind tour of the SciPy 2014 conference which I attended last month. The SciPy conference showcases the latest work in scientific programming using the python language. Astronomy has a strong presence at SciPy and many of the tools and projects that were discussed at SciPy should be of interest to astronomers.
Wednesday, July 9 2014, 11 am
Speaker:
Nemanja Jovanovic (Subaru Telescope)
Title:
SPIE 2014
Abstract:
Nem will chat about cool projects/ideas he came across at the 2014 SPIE meeting.
Wednesday, June 25 2014, 11 am
Speaker:
Ji Hoon Kim (Subaru Telescope)
Title:
Interpreting the sub-linear Kennicutt-Schmidt relationship :
The case for diffuse molecular gas
Abstract:
This paper argues for the sub-linear Kennicutt-Schmidt relation unlike most other studies on the issue. It explains implications of the sub-linear KS relation and possible origins for it.
Wednesday, May 28 2014, 11 am
Speaker:
Sherry Yeh (Subaru Telescope)
Title:
The youngest massive star clusters near the centers of galaxies
Abstract:
I will present a straightforward approach to study the youngest and highly obscured massive star clusters in ground-based MIR observations. The Kennicutt-Schmitt Law does not necessarily operate near the centers of galaxies (CoGs), and the universality of the cluster formation efficiency (CFE) is yet to be validated. Ground-based [NeII] imaging is free from extinction, and it simultaneously delivers high angular resolution and recovers extended emission, critical for surveying CFEs consistently. We mapped the nucleus of NGC 6946 in [NeII] using Subaru Telescope. By comparing the [NeII] emission of young massive clusters (YMCs) 10^4 to 10^5 Msun and extended features, we estimated the CFE to be ~13%, similar to that found in other environments. We will observe YMCs in 4 more galaxies, and spectroscopic followups will constrain the ages and densities of YMCs and HII regions, revealing how stellar feedback couples with the environment.
Wednesday, May 14 2014, 11 am
Speaker:
Ramprasad Rao (ASIAA)
Title:
Detection of a Magnetized Disk around a Very Young Protostar
Abstract:
We present subarcsecond resolution polarimetric observations of the 878 μm thermal dust continuum emission obtained with the Submillimeter Array toward the IRAS 16293-2422 protostellar binary system. We report the detection of linearly polarized dust emission arising from the circumstellar disk associated with the IRAS 16293-2422 B protostar. The fractional polarization of ~= 1.4% is only slightly lower than that expected from theoretical calculations in such disks. The magnetic field structure on the plane of the sky derived from the dust polarization suggests a complex magnetic field geometry in the disk, possibly associated with a rotating disk that is wrapping the field lines as expected from the simulations. The polarization around IRAS 16293-2422 A at subarcsecond angular resolution is only marginally detected.
Wednesday, April 16 2014, 11 am
Speaker:
Yuriko Saito (Subaru Telescope)
Title:
Investigating the coevolution between SMBHs and galaxies at z~3 -our first result-
Abstract:
In the local universe, there is a tight correlation between the massesof super massive black holes (SMBHs) and stars in the spheroidalcomponents (bulge and elliptical galaxies), suggesting that their formationis physically closely related. Various models assuming different physicalmechanisms are proposed to explain the observational result at z=0.Since these models predict different redshift evolution of theSMBH-spheroid mass ratio, it is important to observationally constrainthe mass ratio at high redshift. As the predicted difference becomeslarger at higher redshift, going to higher redshift is better to distinguishamong these models, but at the same time observational difficultiesincrease at higher redshift. By taking into account these factors,we have concluded that z=3-3.5 is practically the best redshift range.However, previous studies have mostly been limited to z<2.We have embarked on (1) systematic near-infrared spectroscopy ofz=3-3.5 QSOs, to derive the SMBH masses, based on the the Balmerbeta emission line width and nearby continuum luminosity,and (2) Subaru LGS-AO near-infrared multi-color imaging observations,to estimate spheroidal stellar masses in the host galaxies of these QSOs.We obtained spectroscopic data for 37 objects, and succeeded to deriveBH masses for 28 objects among them. We have also performed Subaru AOimaging observations of 9 QSOs with estimated SMBH masses, and so farestimated spheroidal stellar mass for 3 objects.In this talk, I will present our first result of SMBH mass - bulgemass ratio for 3 objects.
Wednesday, April 2 2014, 11 am
Speaker:
Barnaby Norris (University of Sydney)
Title:
VAMPIRES - Polarimetric interferometry meets SCExAO
Abstract:
Coronagraphic techniques allow excellent high contrast imaging of targets such as protoplanetary disks, but the crucial innermost regions of such objects lie hidden behind the coronagraph's occulting mask. VAMPIRES - a new module added to the SCExAO system here at Subaru - will image the inner region at resolutions at and beyond the diffraction limit, by combining the proven ultra-high resolution technique of aperture-masking interferometry with extremely precise calibration from differential polarimetry. By imaging the polarised structure of inner disk in scattered starlight, VAMPIRES aims to reveal the gaps, waves and knots which betray the presence of a developing planetary object.
Wednesday, March 19 2014, 11 am
Speaker:
Hong Soo Park (Subaru Telescope)
Title:
Globular Clusters in Massive Elliptical Galaxies
Abstract:
Globular clusters (GCs) are often discovered more than several thousands in a massive galaxy so that they are excellent tool to probe their host galaxy as well as themselves.In this talk, I will present the properties of the GCs in the massive elliptical galaxies.Based on my previous study, photometric properties, kinematics, and chemical abundances of the GCs will be showed.The results will be shortly discussed in terms of the formation of the GCs and their host galaxies.
Wednesday, March 5 2014, 11 am
Speaker:
Akio Inoue (Osaka-sangyo University)
Title:
An updated analytic model of the intergalactic attenuation
Abstract:
Even after the cosmic reionization, neutral hydrogen atoms remain in the intergalactic space and form the "Cosmic Web". This neutral hydrogen web makes a numerous absorption lines in spectra of cosmologically distant objects. This is well known as the Lyman alpha forest (LAF). The most popular analytic model describing a mean amount of this absorption as a function of redshift is Madau (1995). Here, I present a version of this kind of model with the latest statistics of the LAF observed.
Wednesday, February 19 2014, 11 am
Speaker:
Suzanne Frayser (Subaru Telesope)
Title:
Effective Communication of Science: Different Strokes for Different Folks
Abstract:
What is the most effective way to communicate your scientific findings? The answer may seem obvious: By presenting your material in a way that connects with the specific audience that will be reading your work. A scientific paper can use specialized language or jargon to reach colleagues who have a similar background and understanding of the subject. Journals generally have a specific format and style to guide the author’s efforts. However, writing for a website or the press requires a different form of expression, almost a different language, to reach the general public. This audience wants to know what these findings mean to them and why they should care about them. The complexity increases in our international scientific communities when scientists create English drafts of their papers written in their native language. The meaning as well as the words require translation from one culture to another. This presentation will provide examples and guidelines for how to communicate for these different audiences.
Thursday, February 6 2014, 11 am
Speaker:
Masatoshi Imanishi (Subaru Telesope)
Title:
Subaru Adaptive-optics High-spatial-resolution Infrared K- and L'-band Imaging Search for Deeply Buried Dual AGNs in Merging Galaxies
Abstract:
We present the results of infrared K- (2.2 micron) and L'-band (3.8 micron) high-spatial-resolution (<0.2 arcsec) imaging observations of nearby gas- and dust-rich infrared luminous merging galaxies, assisted by the adaptive optics (AO) system on the Subaru 8.2-m telescope (~7 nights observations). We investigate the presence and frequency of red K-L' compact sources, which are sensitive indicators of active galactic nuclei (AGNs), including AGNs that are deeply buried in gas and dust. We observed 29 merging systems and confirmed at least one AGN in all but one system. However, luminous dual AGNs were detected in only four of the 29 systems (14%), despite our method's being sensitive to buried AGNs. For multiple nuclei sources, we compared the estimated AGN luminosities with supermassive black hole (SMBH) masses inferred from large aperture K-band stellar emission photometry in individual nuclei. We found that mass accretion rates onto SMBHs are significantly different among multiple SMBHs, such that larger-mass SMBHs generally show higher mass accretion rates when normalized to SMBH mass. Our results suggest that non-synchronous mass accretion onto SMBHs in gas- and dust-rich infrared luminous merging galaxies hampers the observational detection of kiloparsec-scale multiple active SMBHs. This could explain the significantly smaller detection fraction of kiloparsec-scale dual AGNs when compared with the number expected from simple theoretical predictions. Our results also indicate that mass accretion onto SMBHs is dominated by local conditions, rather than by global galaxy properties, reinforcing the importance of observations to our understanding of how multiple SMBHs are activated and acquire mass in gas- and dust-rich merging galaxies. This result is published as Imanishi et al.
(2014 ApJ 780 106) (arXiv:1312.2031).
Wednesday, January 15 2014, 11 am
Speaker:
Alan Iwasaki (Subaru Telesope)
Title:
Getting high in Hawaii reloaded
Abstract:
Learn how a mild-mannered average person goes to the summit of Mauna Kea and becomes empowered to single-handedly position a two ton instrument 70 feet off the ground with the precision of a thousand of a millimeter while balancing on a 1/2 inch pipe on one foot thereby allowing night observation which validates the universality of the electromagnetic spectrum that inspires a theory of how to save planet Earth...
Or just come and eat free candy.
Wednesday, December 18 2013, 11 am
Speaker:
Sherry Yeh (Subaru Telesope)
Title:
NoMachine: remote desktop access made easy
Abstract:
I will introduce NoMachine, a free software for remote desktop access. NoMachine supports all operating systems, tablets, and smart phones. It also works well with very slow internet connections such as a dialup modem. I will demonstrate NoMachine in this journal club, hopfully to make your life easier working remotely from home, coffee shops, or destinations of your choice.
Friday, December 6 2013, 11 am
Speaker:
Alexandre Bouquin (Universidad Complutense de Madrid)
Title:
Environmental and morphological-type segregation on the evolution of nearby galaxies out of the blue sequence
Abstract:
We have obtained GALEX UV radial surface brightness and color profiles, as well as integrated magnitudes for +2100 galaxies covering ~91% of the S4G/DAGAL volume-limited sample of nearby galaxies (d<40Mpc), and combined these with Spitzer/IRAC-3.6um photometry. The analysis of the (FUV-NUV) vs (NUV-3.6um) color-color diagram reveals both a so-called "blue sequence", where Irr through Sb”s are located, and a "red cloud", where E/S0 reside. This is opposite to the morphology seen in optical CMDs and it mostly due to the degeneracies between SFH of disk galaxies and dust extinction (which strongly correlates the FUV-NUV and NUV-3.6um colors) and could only be seen thanks to the statistics and wide range of galaxy masses and types provided by S4G/DAGAL. We find many early-type spirals evolving off (or into) this "blue sequence" towards (or from) the "red cloud" that we interpret as a sign of strangulation (or re- birth) of the star formation in these galaxies. Such processes lead to distinct FUV-NUV colors, as this color is very sensitive to recent changes in the star formation activity, compared to other colors (optical ones or even NUV-3.6). Special attention is paid to the dependence of this evolution with the morphological type and environment since these (more than simply the stellar mass) seem to determine which galaxies are currently evolving off the blue sequence.
Wednesday, November 13, 2013, 11 am
Speaker:
Josh Walawender (Subaru Telescope)
Title:
A Brief Intro to Git and Github for Scientists
Abstract:
I will give a brief introduction to the version control tool git with an emphasis on how it can be useful in collaborative projects. While developed and used primarily in software projects, git can be a useful workflow tool for writing scientific papers as well.
Wednesday, November 13, 2013, 11 am
Speaker:
Alan Iwasaki (Subaru Telescope)
Title:
Getting high in Hawaii
Abstract:
Learn how a mild-mannered average person goes to the summit of Mauna Kea and becomes empowered to single-handedly position a two ton instrument 70 feet off the ground with the precision of a thousand of a millimeter while balancing on a 1/2 inch pipe on one foot thereby allowing night observation which validates the universality of the electromagnetic spectrum that inspires a theory of how to save planet Earth...
Or just come and eat free candy.
Wednesday, October 30, 2013, 11 am
Speaker:
Yuko Kakazu & Josh Walawender (Subaru Telescope)
Title:
Organizing research papers with Mendeley & Papers
Abstract:
Do you have an ever-growing pile of papers on your computer that is becoming out of control? If so, you are not the only one. With more than 1,000 articles submitted to astro-ph each month, staying on top of the literature is becoming increasingly challenging in today's astronomical research. In this talk, we will introduce you to two commonly used software for managing references: Mendeley and Papers. We will demonstrate how to use these softwares and discuss the pros and cons of each software.
Thursday, October 17, 2013, 11 am
Speaker:
Josh Walawender (Subaru Telescope)
Title:
Project PANOPTES
Abstract:
The goal of Project PANOPTES (Panoptic Astronomical Networked OPtical observatory for Transiting Exoplanets Survey) is to build low cost, reliable, robotic telescopes which can be used to detect transiting exoplanets. Panoptes is an open source, open hardware project which aims to involve citizen scientists and schools in all aspects of science. The hardware is designed to be standardized, using as many commercial off the shelf (COTS) components as possible so that a Panoptes "unit" can be reproduced quickly and easily by students or new team members. In this way, many units can be deployed at many different sites to provide continuous and redundant sky coverage.
Wednesday, October 2, 2013, 11 am
Speaker:
Tadayuki Kodama (NAOJ)
Title:
MAHALO Subaru, ALOHA TMT!
Abstract:
Galaxy formation peaks at 1<z<3. We have been mapping out star formation activities across cosmic times (covering the peak epoch) and environments (from clusters to general fields) with Subaru to sketch how it is propagated with time and how it is affected by surrounding environments. With a huge light collecting power and a superb sptial resolution that TMT will offfer, we will be able to resolve internal physics within galaxies to know why.
Wednesday, September 18, 2013, 11 am
Speaker:
Fumika Oshiyama (Hokkaido University)
Title:
Development of an 8-octant phase-mask coronagraph for the SCExAO/Subaru
Abstract:
An 8-octant phase-mask (8OPM) coronagraph is one of promising approaches for direct imaging of exoplanets because of its simple mask design and relatively small inner working angle (IWA). We have been developing the 8OPM coronagraph for the SCExAO/Subaru. A focal-plane coronagraph mask, an 8OPM, has been manufactured based on the photonic-crystal technology. In addition, we also manufactured a pupil remapping lenses, called modified PIAA (MPIAA), for removing a central obscuration due to a secondary mirror in order to maximize the coronagraphic performance. I present laboratory demonstrations of the MPIAA combined with the 8OPM oronagraph.