The "Cosmic Seagull": A Highly Magnified Disk-like Galaxy at z ≃ 2.8 behind the Bullet Cluster
Artikel i vetenskaplig tidskrift, 2018

We present Atacama Large Millimeter/submillimeter Array measurements of the "Cosmic Seagull," a strongly magnified galaxy at z = 2.7779 behind the Bullet Cluster. We report CO(3-2) and continuum 344 μm (rest-frame) data at one of the highest differential magnifications ever recorded at submillimeter wavelengths (μ up to ∼50), facilitating a characterization of the kinematics of a rotational curve in great detail (at ∼620 pc resolution in the source plane). We find no evidence for a decreasing rotation curve, from which we derive a dynamical mass of (6.3 ± 0.7) × 1010Mowithin r = 2.6 ± 0.1 kpc. The discovery of a third, unpredicted, image provides key information for a future improvement of the lensing modeling of the Bullet Cluster and allows a measure of the stellar mass, , unaffected by strong differential magnification. The baryonic mass is expected to be dominated by the molecular gas content (fgas≤ 80 ± 20%) based on an mass estimated from the difference between dynamical and stellar masses. The star formation rate (SFR) is estimated via the spectral energy distribution (SFR = 190 ± 10 Moyr-1), implying a molecular gas depletion time of 0.25 ± 0.08 Gyr.

galaxies: ISM

galaxies: clusters: individual (1ES0657-558)

galaxies: evolution

gravitational lensing: strong

submillimeter: galaxies


V. Motta

Universidad de Valparaíso

E. Ibar

Universidad de Valparaíso

T. Verdugo

Universidad Nacional Autonoma de Mexico

J. Molina

Universidad de Chile

T. M. Hughes

Chinese Academy of Sciences

University of Science and Technology of China

Universidad de Valparaíso

M. Birkinshaw

University of Bristol

O. López-Cruz

Instituto Nacional de Astrofísica, Óptica y Electrońica

John H Black

Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik, Galaktisk astrofysik

D. Gunawan

Universidad de Valparaíso

Cathy Horellou

Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik, Extragalaktisk astrofysik

J. Magana

Universidad de Valparaíso

Astrophysical Journal Letters

2041-8205 (ISSN) 2041-8213 (eISSN)

Vol. 863 2 L16


Subatomär fysik

Astronomi, astrofysik och kosmologi

Atom- och molekylfysik och optik


Grundläggande vetenskaper



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