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Internal photos of the Laser Synthesizer instrument. Left - top view of optical components including FBG assembly that houses optical filters, couplers and switch; Amonics erbium doped fiber amplifier along with other auxiliary items. Right - bottom view consisting of Centellax RF power amplifier, Sumitomo Mach Zehnder modulator, DC power supplies, and ADAM monitor & control.

MZM Laser Synthesizer, ALMA Project

Internal photos of LORTM instrument. Left - top view of optical components including Sumitomo Mach Zehnder modulators (x2), Centellax RF power amplifiers (x2), Amonics erbium doped fiber amplifier, fiber Bragg grating filters, along with other auxiliary items. Right - bottom view consisting of DC power supplies, ADAM monitor & control, TexaXion laser, and Miteq IF power amplifier.

Local Oscillator Reference Test Module, ALMA Project

$Left panels: The distributions of molecular gas for three MaNGA-selected green valley galaxies (from top to bottom: Galaxy 1, Galaxy 2, and Galaxy 3) based on ALMA CO observations. Middle and right panels: The gas fraction (middle panels) and the star formation efficiency (SFE; right panels) as a function of specific star formation rate (sSFR). The dashed lines show the COLD GASS results based on a sample of galaxies with secure CO detections (see Table 1 of Saintonge et al. (2011)). The small dots in the upper-right two panels represent spaxels located in the bulges. In the bottom-right two panels, the contours represent the distributions in the disks. The solid circles and stars show the median values of the bulge and disk regions, respectively. The red arrows in the top-left panel indicate the upper limits for Galaxy 3. The Spearman’s correlation coefficient is also shown in the lower-right corner of each panel. The figure is taken from Lin et al. (2017, ApJ, 851, 18).$

The role of molecular gas in suppressing star formation in galaxies

Improvement in resolution and sensitivity from SMA subcompact (left, resolution of 2”) to SMA extended (middle, resolution of 0.7”) to ALMA (resolution of 0.26”) towards the high-mass star-forming cores W51 e2 (top) and W51 e8 (bottom). Contours are dust continuum. Red segments indicate magnetic field orientations measured from dust polarization in Band 6 (220 GHz) with ALMA and at 345 GHz with the SMA (Koch et al. 2018, ApJ, 855, 39).

A First Glimpse of ALMA at the High-Mass Star-Forming Region W51

We have realized the epitaxial growth of ultrathin δ-NbN films on 3C-SiC/HRSi substrates. Even with a thickness of 1.3 nm (~3 unit-cells), the δ-NbN film shows a superconducting transition above 8 K. The critical current of 2.7 nm film is 0.59 mA, corresponding to critical current density of 2.2 MA/cm2.

Epitaxial ultrathin NbN superconducting films for Terahertz application

ALMA image of the dust ring (red) and gaseous spirals (blue) of the circumstellar disk AB Aurigae.

Spirals inside a dust gap of a young star forming disk

High-resolution Band 7 continuum negative image of SDP.81. This is the highest-resolution submillimeter observation of a strong lensing galaxy to date.

The Innermost Mass Distribution of the Gravitational Lens SDP.81 from ALMA Observations

Figure 1: ALMA composite image of HH 212, showing a pseudo-disk (green) and a Keplerian disk (bright green) in dust continuum, and a bipolar jet in HCO+ gas (red). (Lee et al. 2014)

ALMA Revealing the Pseudo-disk, Keplerian Rotating disk, and Jet in the Very Young Protostellar System HH 212

NA 12m Vertex prototype antenna at the JVLA site in Socorro, New Mexico.

The Atacama Large Millimeter/submillimeter Array (ALMA) is the largest ground based astronomical telescope to be built. It consists of 66 telescopes operating as an interferometer at mm and submm wavelengths. Located in the Atacama desert in Chile, this scaled-up version of the Submillimeter Array is now officially online with the inauguration ceremony held on March 13, 2013 in Chile. Its large collecting area in combination with its location in a high dry region will permit sensitive observations leading to transformative science of the cool Universe. This instrument will be the preeminent instrument for studies of the relic radiation from the early Universe and of the formation and evolution of stars, planetary systems, galaxies and even the origin of life itself.

ALMA has three main partners: North America, Europe, and East Asia. Taiwan has been invited to participate both by ALMA-Japan and ALMA-North America. In 2005, ASIAA joined the ALMA-Japan project. In 2008, Taiwan joined the ALMA-NA project, with ASIAA as the lead agency for Taiwan. In close collaboration with Chung-Shan Institute of Science and Technology, ASIAA has constructed the East Asia Front End Integration Center (EA FEIC) in Taichung. The center not only assembled and tested the 17 Front End systems to be installed in the ALMA-Japan antennas but had also delivered additionally 5 systems for ALMA-North America, and 4 systems for ALMA-Europe.

ALMA was opened for use by astronomers on September 30, 2011 at its first round of scientific operations, namely, ALMA Cycle 0 Early Science. Out of around 900 applications from astronomers around the world, we have succeeded in leading 8 of the 112 projects accepted. Later in January of 2013, ALMA started its Cycle 1 Early Science operation. 1133 proposals were submitted. 196 proposals were accepted, with 14 of them led by us.