Discovery of optically emitting circumgalactic nebulae around the majority of UV-luminous quasars at intermediate redshift
Sean D. Johnson, Zhuoqi Will Liu, Jennifer I. Li, Joop Schaye, Jenny E. Greene, Sebastiano Cantalupo, Gwen C. Rudie, Zhijie Qu, Hsiao-Wen Chen, Marc Rafelski, Sowgat Muzahid, Mandy C. Chen, Wolfram Kollatschny, Nishant Mishra, Michael Rauch, Fakhri S. Zahedy
arXiv:2404.00088v1 Announce Type: new
Abstract: We report the discovery of large ionized, [O II] emitting circumgalactic nebulae around the majority of thirty UV luminous quasars at $z=0.4-1.4$ observed with deep, wide-field integral field spectroscopy (IFS) with the Multi-Unit Spectroscopy Explorer (MUSE) by the Cosmic Ultraviolet Baryon Survey (CUBS) and MUSE Quasar Blind Emitters Survey (MUSEQuBES). Among the 30 quasars, seven (23%) exhibit [O II] emitting nebulae with major axis sizes greater than 100 kpc, twenty greater than 50 kpc (67%), and 27 (90%) greater than 20 kpc. Such large, optically emitting nebulae indicate that cool, dense, and metal-enriched circumgalactic gas is common in the halos of luminous quasars at intermediate redshift. Several of the largest nebulae exhibit morphologies that suggest interaction-related origins. We detect no correlation between the sizes and cosmological dimming corrected surface brightnesses of the nebulae and quasar redshift, luminosity, black hole mass, or radio-loudness, but find a tentative correlation between the nebulae and rest-frame [O II] equivalent width in the quasar spectra. This potential trend suggests a relationship between ISM content and gas reservoirs on CGM scales. The [O II]-emitting nebulae around the $zapprox1$ quasars are smaller and less common than Ly$alpha$ nebulae around $zapprox3$ quasars. These smaller sizes can be explained if the outer regions of the Ly$alpha$ halos arise from scattering in more neutral gas, by evolution in the cool CGM content of quasar host halos, by lower-than-expected metallicities on $gtrsim50$ kpc scales around $zapprox1$ quasars, or by changes in quasar episodic lifetimes between $z=3$ and $1$.arXiv:2404.00088v1 Announce Type: new
Abstract: We report the discovery of large ionized, [O II] emitting circumgalactic nebulae around the majority of thirty UV luminous quasars at $z=0.4-1.4$ observed with deep, wide-field integral field spectroscopy (IFS) with the Multi-Unit Spectroscopy Explorer (MUSE) by the Cosmic Ultraviolet Baryon Survey (CUBS) and MUSE Quasar Blind Emitters Survey (MUSEQuBES). Among the 30 quasars, seven (23%) exhibit [O II] emitting nebulae with major axis sizes greater than 100 kpc, twenty greater than 50 kpc (67%), and 27 (90%) greater than 20 kpc. Such large, optically emitting nebulae indicate that cool, dense, and metal-enriched circumgalactic gas is common in the halos of luminous quasars at intermediate redshift. Several of the largest nebulae exhibit morphologies that suggest interaction-related origins. We detect no correlation between the sizes and cosmological dimming corrected surface brightnesses of the nebulae and quasar redshift, luminosity, black hole mass, or radio-loudness, but find a tentative correlation between the nebulae and rest-frame [O II] equivalent width in the quasar spectra. This potential trend suggests a relationship between ISM content and gas reservoirs on CGM scales. The [O II]-emitting nebulae around the $zapprox1$ quasars are smaller and less common than Ly$alpha$ nebulae around $zapprox3$ quasars. These smaller sizes can be explained if the outer regions of the Ly$alpha$ halos arise from scattering in more neutral gas, by evolution in the cool CGM content of quasar host halos, by lower-than-expected metallicities on $gtrsim50$ kpc scales around $zapprox1$ quasars, or by changes in quasar episodic lifetimes between $z=3$ and $1$.