Resolving the Interstellar Medium in the Nuclear Region of Two z = 5.78 Quasar Host Galaxies with ALMA

Abstract

We present ALMA observations of the [CII] 158 µm fine structure line and dust continuum emission from two quasars, SDSS J104433., at z=5.78. The ALMA observations at 0.2 resolution map the dust and gas on kpc scales. The spatially resolved emission shows a similar trend of decreasing [CII]-FIR ratios with increasing FIR surface brightnesses as was found in the infrared luminous galaxies with intense star formation. We confirm the velocity gradients of [CII] emission found previously in SDSS J0129-0035. No clear evidence of order motion is detected in SDSS J1044-0125. The velocity maps and PV-diagrams also suggest turbulent gas clumps in both objects. We tentatively detect a [CII] peak offset 4.9 kpc to the East of SDSS J1044-0125. This may be associated with an infalling companion, or node of gas outflow. All these results suggest significant dynamical evolution of the ISM in the nuclear region of these young quasar-starburst systems. We fit the velocity map of the [CII] emission from SDSS J0129-0035 with a rotating disk model. The result suggests a face-on system with an inclination angle of 16 ± 20 • and constrains the lower limit of the host galaxy dynamical mass to be 2.6 × 10 10 M within the [CII] emitting region. It is likely that SDSS J0129-0035, as well as other young quasars with super massive black hole masses on order of 10 7 M to 10 8 M , falls close to the black hole and host galaxy mass relation defined by local galaxies.

Full of Orions: a 200-pc mapping of the interstellar medium in the redshift-3 lensed dusty star-forming galaxy SDP.81

“…The [C ii]/FIR varies by > 1.5 dex on sub-kpc scales: while the outskirts of the system show efficient [C ii] cooling (L [CII] /L [CII] = 10 −2.5 − 10 −2.0 , the FIR-bright star-forming clumps show a pronounced [C ii]/FIR deficit, down to 10 −3.5 . et al 2018;Litke et al 2019;Rybak et al 2019;Wang et al 2019). As shown inFig.…”

“…We denote the 3σ upper limits on t dep (regions with S/N≥ 3 in FIR and < 3 in CO(3-2)) and 3σ lower limits (S/N < 3 in FIR and ≥ 3 in CO(3-2)).with the FIR (SFR) surface density (Herrera-Camus et al 2015). Recently, resolved [C ii] studies in z > 1 DSFGs have been presented by Gullberg et al (2018); Lamarche et al (2018); Litke et al (2019) and Rybak et al (2019), revealing a pronounced [C ii]/FIR deficit down to L [CII] /LFIR 10 −4 .Similarly pronounced [C ii]/FIR deficits have been found in resolved ALMA observations of z ≥ 5 quasar hosts (e.g.,Wang et al 2019;Neeleman et al 2019;Venemans et al 2019). Here, we consider both the source-averaged and resolved [C ii]/FIR ratio in SDP.81, and compare it to local and high-redshift studies.…”

What do observations tell us about the highest-redshift supermassive black holes?

“…Importantly, sub-mm observations also probe several ISM emission lines, most notably [C ii] λ157.74 μm, which allow to study the dynamics of the quasar hosts. Since the first detection of [C ii] in the z 6.4 quasar J1148+5251 (Maiolino et al 2005), such measurements have grown to become a booming "industry", with several teams pursuing increasingly better data for ever growing samples (for an impression of this progress, see, e.g., Venemans et al 2012Venemans et al , 2016Venemans et al , 2017Venemans et al , 2019Wang et al 2013Wang et al , 2019bWillott et al 2013Willott et al , 2015Willott et al , 2017Trakhtenbrot et al 2017b;Decarli et al 2018;Izumi et al 2018Izumi et al , 2019. In many cases, the spatially resolved [C ii] line velocity maps show signs of ordered, rotationdominated gas dynamics ( Fig.…”

“…Indeed, deeper and higher resolution ALMA data obtained for some systems show no (or very limited) evidence for rotation-dominated gas structures, thus highlighting the limitations of such assumptions. Examples of such cases, and of more elaborate analyses, can be found in, e.g., Neeleman et al (2019), Venemans et al (2019), and Wang et al (2019b).…”

Effect of mass loss due to stellar winds on the formation of supermassive black hole seeds in dense nuclear star clusters

“…Discovery of more than two hundred supermassive black holes (SMBHs) with masses 10 9 M within the first ∼ Gyr after the Big Bang (Fan et al 2001;Willott et al 2010;Mortlock et al 2011;Wu et al 2015;Bañados et al 2018;Matsuoka et al 2018;Wang et al 2019;Shen et al 2019;Matsuoka et al 2019) have challenged our general understanding of black hole growth and formation. How these massive objects formed and grew over cosmic time is one of the biggest puzzles to solve in astrophysics (Smith & Bromm 2019;Inayoshi et al 2019;Latif & Schleicher 2019).…”