[Speaker 1]
Shino Nagisa
Affiliation
D2, SOKENDAI, Mitaka（supervisor : Mareki Honma）
[Title]
TBA
[Abstract]
TBA

[Speaker 2]
Katsuya Hashizume
Affiliation
D1, SOKENDAI, Mitaka（supervisor : Ken Ohsuga）
[Title]
The super-critical accretion disk and outflow; an origin of the
ULX nebula
[Abstract]
The accretion disks around black holes (BHs) are believed to drive
high energy astrophysical phenomena, such as high-energy radiation,
disk winds, and jets of active galactic nuclei and black hole
binaries. However, a central engine of ultra-luminous X-ray sources
(ULXs) is still an enigma. Since the luminosity of the ULXs exceeds
the Eddington luminosity of stellar mass BH (~10M_sun), the standard
disk (sub-Eddington disk) around the black hole of ~< 10Msun cannot explain the ULXs. Hence, two possibilities are suggested; (1) stellar mass BH with super-critical accretion disk of which the luminosity is larger than Eddington luminosity (2) standard disk around intermediate mass BH (IMBH) of > 100Msun.
Recently, multi-wavelength observations revealed that some of ULXs are
surrounded by nebulae (ULX nebulae). The origin of the nebulae has not
been understood yet, though it might be a key phenomenon to resolve
the central engine of the ULXs. Here, we investigate super-critical
accretion disk around stellar mass BH by two-dimensional
radiation-hydrodynamics simulations. We confirmed that super-critical
accretion disk drives strong outflows with large opening-angle (20-85
degree). The kinetic energy of the outflows is roughly consistent with
the luminosity injected into ULX nebulae, implying that our results
support the scenario of the stellar mass BHs with super-critical
accretion disks.

[Speaker 1]
masafusa Onoue
M1, SOKENDAI, Mitaka（supervisor : Nobunari Kashikawa）
[Title]
Exploring the Early Universe with High-z Quasars.

[Speaker 2]
Ryosuke Nagasawa
M1, SOKENDAI, Mitaka（supervisor : Hideo Hanada）
[Title]
Review of Lunar Science with Lunar Laser Ranging

[Speaker 3]
Gabriel Giono
D1, SOKENDAI, Mitaka（supervisor : Yoshinori Suematsu）
[Title]
An introduction to CLASP

[Speaker 1]
Nobuharu Sako
[Title]
Time evolution of X-ray jet’s velocity
[Abstract]
An X-ray jet is a kind of flares in the Sun. The model of X-ray jets based on magnetic reconnection (Shibata et al. 1992) predicts that two flows with the different velocities are included in one X-ray jet. The velocity of one flow roughly equals to Alfven velocity (~1000 km/s), and the flow is accelerated by the magnetic force. The other one is
accelerated by the pressure gradient and its velocity is similar to the sound velocity (~200 km/s). However, the observational results (e.g. Shimojo et al. 2000) before the Hinode era show that the velocities of most X-ray jets are slower than the sound velocity.
Because the X-ray telescope (XRT) aboard the Hinode satellite has capability to observe the corona with the high temporal (< 1 min) and high spatial (~ 1 arcsec) resolutions, the XRT data revealed that an X-ray jet includes two components with the different velocities (Cirtain et al. 2007). The properties of the components have some differences from the model. For example, the components are not observed simultaneously. One component with sound velocity continues to appear until the peak time of the X-ray jet. The other one with Alfven velocity appear transiently. There is only one report using four X-ray jets by Cirtain et al. (2007) and their result does not show the time evolution of the velocity in X-ray jets, yet. In order to reveal the evolution of the X-ray jet's velocity, and investigate how the high velocity component occurs transiently in an X-ray jet, we detected 13 polar X-ray jets from the coronal data observed with XRT and investigated the time evolution of the velocity of the X-ray jets. The result shows that it is common that an X-ray jet includes the plural components with the different velocities. However, we could detect component with Alfven velocity in only three of the 13 events. In the talk, I introduce our data analysis and show the details of our result.

[Speaker 1]
Jungmi Kwon
[Title]
NEAR INFARED CIRCULAR POLARIZATION IMAGES OF NGC 6334 V
[Abstract]
We present results from deep imaging polarimetry measurements of circularly and linearly polarized light towards the massive star forming region NGC 6334-V. These observations show high degrees of circular polarization (CP) in the Ks band of as much as 22 % with an asymmetric positive/negative pattern, measured in the infrared nebula associated with the outflow. The CP region is very extended (~80″ or 0.65 pc). Both the large CP and the extended size of the CP region are comparable to those seen in the Orion CP region. The CP pattern is shifted along the axial axis and such an asymmetry does not conform to the classical alternating symmetry seen in other objects and models.
The asymmetry may be a clue indicating the range of influence of a helical field. Three-dimensional Monte Carlo light-scattering models are used to show that this may occur with a scattering geometry, which contains a dusty envelope surrounding the accretion disk as well as aligned grains. The detection of the large and extended CP in this source and the Orion supports the CP origin of the biological homochirality on Earth.
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[Speaker 2]
Anjali John K
[Title]
Association of Polar faculae with the Polar magnetic patches as observed by Hinode
[Abstract]
The polar region of the Sun, as observed with Hinode SOT/SP is found to be covered by patches that harbour strong magnetic field and that the large unipolar patches with flux > 10^18 Mx determine the polarity of the polar field. It is also observed that there are small
bipolar patches (< 1018Mx) with balanced flux in the polar region. The polar faculae, the small-scale bright magnetic structures observed at heliographic latitudes > 70 deg., have been considered as a good proxy for the polar magnetic field. The aim of this study is to understand the magnetic properties of faculae, which are believed to be associated with the polar magnetic patches. We analysed data of the north polar region taken by the Hinode/SOT- spectropolarimeter (SP) in September 2007. There are patches without faculae and they outnumber those with faculae. Faculae are present in all the patches with flux > 10^19 Mx. Magnetic patches are not uniformly bright but contain smaller faculae inside. We find that a positive correlation exists between total flux and intensity of faculae within the magnetic patches and that the faculae intensity depends on cosine of the heliocentric angle .

[Speaker 1]
Nobuyuki Sakai
[Title]
Absolute Proper Motion of CB 3 Away from the Galactic Plane Measured with VERA in a Galactic Superbubble
[Abstract]
TBA
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[Speaker 2]
Daehyun Oh
[Title]
Powerful high-contrast imaging techniques on direct detection of exoplnaets
[Abstract]
Direct detections of very faint exoplanets and brown dwarfs near bright stars are essential in understanding substellar for- mation and evolution around stars. The task is dauntingly difficult. The exoplanet or brown dwarf image is usually much fainter than the background from the brilliant PSF image. Aside from the Poisson noise, ground-based tele- scopes suffer from atmospheric turbulence that produces random short-lived speckles that mask faint companions. I will talk about two techniques called ADI and LOCI, can be used on ground-based altitude/ azimuth telescopes to subtract a significant fraction of the stellar quasistatic noise.