SUPER VI. A giant molecular halo around a z similar to 2 quasar

• We present the discovery of copious molecular gas in the halo of cid_346, a z=2.2 quasar studied as part of the SINFONI survey for Unveiling the Physics and Effect of Radiative feedback (SUPER). New Atacama Compact Array (ACA) CO(3-2) observations detect a much higher flux (by a factor of 14 +/- 5) than measured on kiloparsec scales (r less than or similar to 8 kpc) using previous snapshot Atacama Large Millimeter/submillimeter Array data. Such additional CO(3-2) emission traces a structure that extends out to r similar to 200 kpc in projected size, as inferred through direct imaging and confirmed by an analysis of the uv visibilities. This is the most extended molecular circumgalactic medium (CGM) reservoir that has ever been mapped. It shows complex kinematics, with an overall broad line profile (FWHM=1000 km s(-1)) that is skewed towards redshifted velocities up to at least v similar to 1000 km s(-1). Using the optically thin assumption, we estimate a strict lower limit for the total molecular CGM mass observed by ACA of M-mol(CGM) > 10(10) M-circle dot. There is however room for up to M-mol(CGM) similar to 1.7 x 10(12) M-circle dot, once optically thick CO emission with alpha(CO) = 3.6 M-circle dot (K km s(-1) pc(2))(-1) and LCO(3- 2)'/LCO(1-0)' = 0.5 are assumed. Since cid_346 hosts quasar-driven ionised outflows and since there is no evidence of merging companions or an overdensity, we suggest that outflows may have played a crucial rule in seeding metal-enriched, dense gas on halo scales. However, the origin of such an extended molecular CGM remains unclear.

Ämnesord

NATURVETENSKAP  -- Fysik -- Astronomi, astrofysik och kosmologi (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Astronomy, Astrophysics and Cosmology (hsv//eng)

NATURVETENSKAP  -- Fysik -- Atom- och molekylfysik och optik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Atom and Molecular Physics and Optics (hsv//eng)

NATURVETENSKAP  -- Geovetenskap och miljövetenskap -- Geofysik (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences -- Geophysics (hsv//eng)

Nyckelord

galaxies: halos

galaxies: high-redshift

intergalactic medium

galaxies: active

submillimeter: galaxies

quasars: individual: cid_346

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