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Activity Report of Commission J
August 2015 to December 2015
December 28, 2015
Kenta Fujisawa (Yamaguchi University)

ALMA projectLatest scientific topics from ALMA press release:
Nov 24, 2015 ALMA Links with Other Observatories to Create Earth-size Telescope

The Atacama Large Millimeter/submillimeter Array (ALMA) continues to expand its
power and capabilities by linking with other millimeter-wavelength telescopes in Europe
and North American in a series of very long baseline interferometry (VLBI) observations.
In VLBI, data from two or more telescopes are combined to form a single virtual telescopethat spans the geographic distance between them. The most recent of these experimentswith ALMA formed an Earth-size telescope with extraordinarily fine resolution.
These experiments are an essential step in including ALMA in the Event Horizon
Telescope (EHT), a global network of millimeter-wavelength telescopes that will have thepower to study the supermassive black hole at the center of the Milky Way inunprecedented detail.
Before ALMA could participate in VLBI observations, it first had to be upgraded adding anew capability known as a phased array. This new version of ALMA allows its 66 antennas
to function as a single radio dish 85 meters in diameter, which then becomes one element
in a much larger VLBI telescope.
The first test of ALMA's VLBI capabilities occurred on 13 January 2015, when ALMA
successfully linked with the Atacama Pathfinder Experiment Telescope (APEX), which isabout two kilometers from the center of the ALMA array.
On 30 March 2015, ALMA reached out much further by linking with the Institut deRadioastronomie Millimetrique's (IRAM) 30-meter radio telescope in the Sierra Nevada ofsouthern Spain. Together they simultaneously observed the bright quasar 3C 273. Datafrom this observation were combined into a single observation with a resolution of 34
microarcseconds. This is equivalent to distinguish an object of less than ten centimeters on
the Moon, seen from Earth.
The most recent VLBI observing run was performed on 1-3 August 2015 with six of theNational Radio Astronomy Observatory's (NRAO) Very Long Baseline Array (VLBA)
antennas. This combined instrument formed a virtual Earth-size telescope and observed thequasar 3C 454.3, which is one of the brightest radio beacons on the sky, despite lying at adistance of 7.8 billion light-years. These data were first processed at NRAO andMIT-Haystack in the United States and further post-processing analysis is being performedat the Max Planck Institute for Radio Astronomy (MPIfR) in Bonn, Germany.
The new observations are a further step towards global interferometric observations with

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ALMA in the framework of the Global mm-VLBI Array and the Event Horizon Telescope,with ALMA as the largest and the most sensitive element. The addition of ALMA tomillimeter VLBI will boost the imaging sensitivity and capabilities of the existing VLBI
arrays by an order of magnitude.

(Credit: A. Angelich, NRAO/AUI/NSF)

Activities of meetings
Japan SKA Science Meeting on Cosmic Magnetism 2015
Date: September 17 - 19, 2015
Venue: Kagoshima University
Although the origin of cosmic magnetism has not been revealed yet, magnetic field plays animportant role in high energy phenomena such as stars, compact stars, galaxies, clusters ofgalaxies in various scales. Observation of the cosmic magnetic field is one of key science by theSquare Kilometer Array (SKA) project, huge radio interferometry, in which construction isgetting ready. One can expect that details of three-dimensional magnetic field structure arerevealed by SKA. So we invite top researchers in this field from the world as well as a domestic
researchers, and held a workshop to review the status of the research.

THz Astronomy in Antarctica
Date: November 18 - 19, 2015
Venue: National Astronomical Observatory of Japan
Thanks to its excellent observational condition, the South Pole is paid much attention from allover the world as an observation base for radio to infrared astronomy. The Japanese antarctic
astronomy consortium led by University of Tsukuba plans to construct a 10m THz telescope atantarctic inland area. A plan of 30m telescope which would be the next large plan to TMT isalso considered. At this workshop, new science cases opened by THz observation at the South
Pole would be discussed.

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Workshop for ALMA Large Proposal of gAlactic Cold gAs (ALPACA) Survey
Date: December 1-3, 2015
Venue: National Astronomical Observatory of Japan
Galaxies are multicomponent system mainly consisting of dark matter (DM), stars andinterstellar medium (mainly cold gas). The evolution of DM and stellar component have been
investigated by means of numerical simulations and large galaxy surveys at optical andnear-infrared

wavelengths.

However,

theevolutionof

thecoldgascomponent(molecules/atoms) remains poorly explored. The redshift range of z<~2 is the era in which thecurrent Hubble sequence emerges, as well as the era for disk galaxies converting their cold gas
to stars then developing their galactic disks. Further, one can expect larger and homogeneousdata set of stellar/ionized gas/atomic gas of galaxies with the new-generation instruments suchas HSC, PFS, and SKA. To understand the galaxy evolution at z<~2, namely the second half ofthe cosmic history, it is important to investigate the molecular gas component statistically, since
it links the information of other components (stellar/ionized gas/atomic gas) of galaxies.
We are now planning ALPACA survey (ALMA Large Proposal of gAlactic Cold gAs) aiming atinvestigating statistical properties (“amount”, such as cold gas mass function) and/or detailed“spatial distribution” and “kinematics” of molecular gas of galaxies at z<~2. To design adesirable survey that can provide scientifically important and versatile data, we must list up themissing pieces for understanding the galaxy evolution, and discuss their importance. The
workshop consists of invited review talks and contributed talks. Sufficient time will be sparedfor discussions. We are willing to discuss galaxy evolution regardless of the means (numericalsimulations/semi-analytic models/observations at all wavelengths)!
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13th Mizusawa VLBI observatory Users’ Meeting
Date: September 24 - 25, 2015
Venue: Mizusawa VLBI observatory of NAOJ

East Asian ALMA Science Workshop 2015
Date: December 8 - 11, 2015
Venue: I-site Nanba in Osaka
The National Astronomical Observatory of Japan (NAOJ) and the Osaka Prefecture University
are pleased to announce the annual “East Asian ALMA Science Workshop 2015”, to be held on
December 8 - 11, at the I-site Nanba in Osaka Prefecture. This is the annual joint ALMA
science workshop that involves all three East Asian ALMA partners (Japan, Taiwan and Korea).
The main aim of this workshop is to continue to promote and stimulate international
collaboration among the researchers in the EA partners, by reviewing and sharing the mostrecent ALMA science results from the first 4 years of ALMA operation. With the new observing
modes such as long baselines and high frequencies available for cycle 3, now is a good time toreview what has been achieved so far and discuss the future prospects for cycle 4 and beyond.

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We plan to hold discussion sessions in order to have opportunities for closer communication
among the researchers in related fields.

In addition, we plan to have ample time for discussing“Large Proposals”, which is a new framework that is expected to start from cycle 4.
ALMA Workshop on Mass Accretion Mechanism at 1kpc to 1pc in the center of AGN
Date: December 21 - 22, 2015
Venue: National Astronomical Observatory of Japan

ALMA workshop: "ALMA deep surveys on GOODS-S and beyond"
Date: December 15 - 16, 2015
Venue: Institute of Astronomy, The University of Tokyo

B mode from SpacePart 1: The Science goals, status of spaceborne projects, foregrounds
Part 2: Mission design, technologies and challenges for the spaceborne observations
Dates: December 10 - 16, 2015
Venue: Lecture Hall, Kavli IPMU main building
The goal of the workshop is to discuss the science goals, status of CMB polarization projects,
foregrounds and mission design, technologies and challenges for the spaceborne observations ofCMB polarization to detect primordial gravitational waves and thus to prove the inflation theory.
The workshop will be the first meeting where the LiteBIRD mission is focused on.