TY - JOUR
T1 - Planck's dusty GEMS
T2 - IV. Star formation and feedback in a maximum starburst at z = 3 seen at 60-pc resolution
AU - Cañameras, R.
AU - Nesvadba, N.
AU - Kneissl, R.
AU - Frye, B.
AU - Gavazzi, R.
AU - Koenig, S.
AU - Le Floc'h, E.
AU - Limousin, M.
AU - Oteo, I.
AU - Scott, D.
N1 - Funding Information:
Acknowledgements. We thank the anonymous referee for comments that helped improve the paper. We also thank the ALMA Regional Center in Grenoble for their support with preparing these observations and the ALMA staff in Chile for carrying out the observations. R.C. would like to thank Claudio Grillo for useful discussions and comments. NPHN acknowledges support through a JAO visitor grant, and wishes to thank the ALMA staff in Vitacura for interesting scientific discussions and their great hospitality during an extended stay in early 2016. She also wishes to thank Matt Lehnert for having pointed out that the Kennicutt relation of star formation and FIR luminosity has initially been derived for a Salpeter, not a Chabrier IMF. M.L. acknowledges CNRS and CNES for support. This paper makes use of the following ALMA data: ADS/JAO.ALMA#2015.1.01518.S. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), NSC and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ. I.O. acknowledges support from the European Research Council in the form of the Advanced Investigator Programme, 321302, cosmicism.
Publisher Copyright:
© ESO 2017.
PY - 2017/8/1
Y1 - 2017/8/1
N2 - We present an analysis of high-resolution ALMA interferometry of CO(4-3) line emission and dust continuum in the "Ruby" (PLCK-G244.8+54.9), a bright, gravitationally lensed galaxy at z = 3.0 discovered with the Planck all-sky survey. The Ruby is the brightest of Planck's dusty GEMS, a sample of 11 of the brightest gravitationally lensed high-redshift galaxies on the extragalactic sub-mm sky. We resolve the high-surface-brightness continuum and CO line emission of the Ruby in several extended clumps along a partial, nearly circular Einstein ring with 1.4′′ diameter around a massive galaxy at z = 1.5. Local star-formation intensities are up to 2000 MȮ yr-1 kpc-2, amongst the highest observed at high redshift, and clearly in the range of maximal starbursts. Gas-mass surface densities are a few × 104MȮ pc-2. The Ruby lies at, and in part even above, the starburst sequence in the Schmidt-Kennicutt diagram, and at the limit expected for star formation that is self-regulated through the kinetic energy injection from radiation pressure, stellar winds, and supernovae. We show that these processes can also inject sufficient kinetic energy and momentum into the gas to explain the turbulent line widths, which are consistent with marginally gravitationally bound molecular clouds embedded in a critically Toomre-stable disk. The star-formation efficiency is in the range 1-10% per free-fall time, consistent with the notion that the pressure balance that sets the local star-formation law in the Milky Way may well be universal out to the highest star-formation intensities. AGN feedback is not necessary to regulate the star formation in the Ruby, in agreement with the absence of a bright AGN component in the infrared and radio regimes.
AB - We present an analysis of high-resolution ALMA interferometry of CO(4-3) line emission and dust continuum in the "Ruby" (PLCK-G244.8+54.9), a bright, gravitationally lensed galaxy at z = 3.0 discovered with the Planck all-sky survey. The Ruby is the brightest of Planck's dusty GEMS, a sample of 11 of the brightest gravitationally lensed high-redshift galaxies on the extragalactic sub-mm sky. We resolve the high-surface-brightness continuum and CO line emission of the Ruby in several extended clumps along a partial, nearly circular Einstein ring with 1.4′′ diameter around a massive galaxy at z = 1.5. Local star-formation intensities are up to 2000 MȮ yr-1 kpc-2, amongst the highest observed at high redshift, and clearly in the range of maximal starbursts. Gas-mass surface densities are a few × 104MȮ pc-2. The Ruby lies at, and in part even above, the starburst sequence in the Schmidt-Kennicutt diagram, and at the limit expected for star formation that is self-regulated through the kinetic energy injection from radiation pressure, stellar winds, and supernovae. We show that these processes can also inject sufficient kinetic energy and momentum into the gas to explain the turbulent line widths, which are consistent with marginally gravitationally bound molecular clouds embedded in a critically Toomre-stable disk. The star-formation efficiency is in the range 1-10% per free-fall time, consistent with the notion that the pressure balance that sets the local star-formation law in the Milky Way may well be universal out to the highest star-formation intensities. AGN feedback is not necessary to regulate the star formation in the Ruby, in agreement with the absence of a bright AGN component in the infrared and radio regimes.
KW - Galaxies: ISM
KW - Galaxies: evolution
KW - Galaxies: high-redshift
KW - Galaxies: star formation
KW - Galaxies: starburst
KW - Submillimeter: galaxies
UR - http://www.scopus.com/inward/record.url?scp=85028460594&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85028460594&partnerID=8YFLogxK
U2 - 10.1051/0004-6361/201630186
DO - 10.1051/0004-6361/201630186
M3 - Article
AN - SCOPUS:85028460594
SN - 0004-6361
VL - 604
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
M1 - A117
ER -