We present Keck/Keck Cosmic Web Imager (KCWI) integral field spectrograph observations of the complex system surrounding SMM J02399-0136 (a lensed z = 2.8 sub-mm galaxy), including an associated Lyα nebula, a dust-obscured, broad-absorption-line quasar, and neighboring galaxies. At a 3σ surface brightness contour of 1.6 × 10-17 erg s-1 cm-2 arcsec-2, the Lyα nebula extends over 17 arcsec (≈140 physical kpc) and has a total Lyα luminosity of (uncorrected for lensing). The nebula exhibits a kinematic shear of over 100 pkpc with lowest velocities east of SMM J02399-0136 and increasing to the southwest. We also discover a bright, Lyα emitter, separated spatially and kinematically from the nebula, at a projected separation of ≈60 kpc from the quasar. This source has no clear central counterpart in deep Hubble Space Telescope imaging, giving an intrinsic Lyα rest-frame equivalent width greater than 312 A (5σ). We argue that this "dark cloud" is illuminated by the quasar with a UV flux that is orders of magnitude brighter than the emission along our sightline. This result confirms statistical inferences that luminous quasars at z < 2 emit UV radiation anisotropically. Future KCWI observations of other lines, e.g., Lyβ, He ii, C iv, etc, and with polarimetry will further reveal the origin of the Lyα nebula and nature of the dark cloud.

Li, Q., Cai, Z., Prochaska, J., Battaia, F., Ivison, R., Falgarone, E., et al. (2019). Discovery of a Lyα-emitting Dark Cloud within the z ∼ 2.8 SMM J02399-0136 System. THE ASTROPHYSICAL JOURNAL, 875(2) [10.3847/1538-4357/ab0e6f].

Discovery of a Lyα-emitting Dark Cloud within the z ∼ 2.8 SMM J02399-0136 System

Cantalupo S.;
2019

Abstract

We present Keck/Keck Cosmic Web Imager (KCWI) integral field spectrograph observations of the complex system surrounding SMM J02399-0136 (a lensed z = 2.8 sub-mm galaxy), including an associated Lyα nebula, a dust-obscured, broad-absorption-line quasar, and neighboring galaxies. At a 3σ surface brightness contour of 1.6 × 10-17 erg s-1 cm-2 arcsec-2, the Lyα nebula extends over 17 arcsec (≈140 physical kpc) and has a total Lyα luminosity of (uncorrected for lensing). The nebula exhibits a kinematic shear of over 100 pkpc with lowest velocities east of SMM J02399-0136 and increasing to the southwest. We also discover a bright, Lyα emitter, separated spatially and kinematically from the nebula, at a projected separation of ≈60 kpc from the quasar. This source has no clear central counterpart in deep Hubble Space Telescope imaging, giving an intrinsic Lyα rest-frame equivalent width greater than 312 A (5σ). We argue that this "dark cloud" is illuminated by the quasar with a UV flux that is orders of magnitude brighter than the emission along our sightline. This result confirms statistical inferences that luminous quasars at z < 2 emit UV radiation anisotropically. Future KCWI observations of other lines, e.g., Lyβ, He ii, C iv, etc, and with polarimetry will further reveal the origin of the Lyα nebula and nature of the dark cloud.
Articolo in rivista - Articolo scientifico
cosmology: observations; galaxies: formation; galaxies: high-redshift; intergalactic medium; quasars: general;
English
2019
875
2
130
none
Li, Q., Cai, Z., Prochaska, J., Battaia, F., Ivison, R., Falgarone, E., et al. (2019). Discovery of a Lyα-emitting Dark Cloud within the z ∼ 2.8 SMM J02399-0136 System. THE ASTROPHYSICAL JOURNAL, 875(2) [10.3847/1538-4357/ab0e6f].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/372615
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