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阿塔卡瑪大型毫米及次毫米波陣列計畫(ALMA)

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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.

阿塔卡瑪大型毫米波及次毫米波陣列（ALMA）是目前最大的地面望遠鏡興建計畫，由66座望遠鏡組成一個毫米波及次毫米波段的干涉儀，可視為次毫米波陣列的擴大版，這座位處智利阿塔卡瑪沙漠的望遠鏡，於2013年3月正式舉行開幕儀式。這不僅代表一巨型望遠鏡陣列的主要系統已全部完工，也宣告「ALMA」國際合作計畫之成功。由於集光面積大，加上位於高而乾燥區域的特性，將使得ALMA能進行靈敏的觀測，可望對冷宇宙研究產生革命性影響。此儀器將是研究早期宇宙遺留輻射、恆星形成與演化、行星系統、星系、甚至生命起源的利器。

本計畫的三個主要合作夥伴為北美、歐洲及東亞。臺灣分別受到ALMA日本計畫（ALMA-J）與ALMA北美計畫（ALMA-NA）的邀請而參與本計畫。2005年本所加入ALMA-J，2008年臺灣加入ALMA-NA，本所擔任臺灣的執行機構。本所與中山科學研究院航空研究所於台中合作建立「東亞接收機前段整合測試中心」（EA FEIC）。這個測試中心負責組裝及測試前段次系統，不但成功提前完成原本負責之所有東亞前段次系統(17 套)，更協助北美與及歐洲團隊另外完成 9 套前段次系統的交付。

ALMA 在 2011 年 9 月 30 日正式開放學術使用，利用已經通過運轉測試的天線進行先期科學觀測。到目前為止，ALMA 已兩次公開向全球天文研究學者徵求觀測計畫書，分別稱為 Cycle 0 與 Cycle 1。在總共徵得兩千餘份觀測計劃書中，只有三百餘份通過嚴格的審查。觀測計畫通過審核與否,主要是由審查委員會按送審計畫的科學價值加以評量。臺灣在此激烈的競爭下，總共通過了二十餘份計劃書，取得了亮眼的成績!