1 ALMA Science Results ALMA Detects Ethyl Cyanide on Titan ALMA detected C 2 H 5 CN in 27 rotational...

1 ALMA Science Results

ALMA Detects Ethyl Cyanide on Titan• ALMA detected C2H5CN in 27

rotational lines at 1.3mm– HC3N, CH3CN and CH3CCH

simultaneously detected– Emission from these species peak in

the northern (spring) hemisphere– Emission from EtCN peaks in the

autumn hemisphere– Titan was calibrator for unpublished

archival data• Distributions consistent with short

chemical lifetime (0.4yr) for EtCN– Modeling suggests upper

atmosphere production– ALMA observations should detect

changes with seasons on Titan

Cordiner et al. 2014


ALMA Detects Interconnecting Streamer in Binary GG Tau

• Can nature form planets in multiple star systems?

• ALMA revealed a streamer channeling gas from a massive outer disk to the inner disk in this hierarchical triple system– Flow appears capable of

sustaining the 1 Mjupiter inner disk beyond the accretion lifetime, leaving time for planet formation to occur there.

– Planets may form here!

A Dutrey et al. Nature 514, 600-602 (2014)

CO J=6-5 data. Black: integrated area, blue: approaching gas, red: receding gas, Stars: Aa (south) and Ab (north). Ellipses: ring edge. Spectra illustrate velocities.


ALMA Detects iso-propyl cyanide• Detection suggests branched carbon-

chain molecules may be generally abundant in the ISM

• Both isomers are produced within or upon dust grain ice mantles by radical addition

• Detection bodes well for the presence in the ISM of amino acids which also show side-chain structure

• Suggests a further link between interstellar chemistry and the molecular composition of meteorites for which branched amino acids are even found to dominate over their straight-chain isomers

Examples of transitions of i-PrCN and n-PrCN toward the northern hot core of Sgr B2(N).(A and B) Continuum-subtracted spectrum observed with ALMA in black, the preliminary model including all identified molecules in green, and the synthetic spectra of i-PrCN and n-PrCN, respectively, in red.

A Belloche et al. Science 2014;345:1584-1587


ALMA OBSERVATIONS OF THE ANTENNAE GALAXIES. I. A NEW WINDOW ON A PROTOTYPICAL MERGER

• Filaments identified with beads-on-a-string morphology

• Clear evolutionary sequence emerges

• Diffuse GMCs beget protoclusters beget embedded clusters beget emerging clusters beget young clusters beget old clusters.

• The lifetime of a GMC in a star formation region is of order 10 Myr

Bradley C. Whitmore et al. 2014 ApJ 795 156

(L) CO J=3-2 knots, (C) 3.7 GHz emission, (R) optical clusters in the Long-Thin filamentGreen contours (20, 40, 60 K km s−1) show CO emission; yellow contours (50, 150 μJy beam−1) show radio emission; and orange provides information about the optical clusters.


Starburst Nuclear Ring Imaged by ALMA in NGC1614

• ALMA resolved CO J=6-5 and 435m continuum emission in this 68Mpc distant LIRG.– Knots in a molecular ring at 100 pc<r<350 pc are clumpy, broad

(dV~40 km/s)– Star formation rate in the ring is ~100 Msunyr-1 kpc-2

– Absence of nuclear emission rules out a Compton-thick active nucleus– ΣSFR to Σgas is 10x expectations from KS, perhaps caused by outward

propagation of the central starburst Xu et al 1411.1111


The 1999 Dream vs 2014 Reality

1 ALMA Science Results ALMA Detects Ethyl Cyanide on Titan ALMA detected C 2 H 5 CN in 27 rotational...

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