On the dust and gas components of the $z$ = 2.8 gravitationally lensed quasar host RX J0911.4+0551

Abstract

Observations by the Atacama Large Millimetre/sub-millimetre Array of the 358 GHz continuum emission of the gravitationally lensed quasar host RX J0911.4+0551 have been analysed. They complement earlier Plateau de Bure Interferometer observations of the CO(7-6) emission. The good knowledge of the lensing potential obtained from Hubble Space Telescope observations of the quasar makes a joint analysis of the three emissions possible. It gives evidence for the quasar source to be concentric with the continuum source within 0.31 kpc and with the CO(7-6) source within 1.10 kpc. It also provides a measurement of the size of the continuum source, 0.76 ± 0.04 kpc FWHM, making RX J0911.4+0551 one of the few high redshift galaxies for which the dust and gas components are resolved with dimensions being measured. Both are found to be very compact, the former being smaller than the latter by a factor of ∼3.4±0.4. Moreover, new measurements of the CO ladder − CO(10-9) and CO(11-10) − are presented that confirm the extreme narrowness of the CO line width (107±20 km s −1 on average). Their mere detection implies higher temperature and/or density than for typical quasar hosts at this redshift and suggests a possible contribution of the central AGN to gas and dust heating. The results are interpreted in terms of current understanding of galaxy evolution at the peak of star formation. They suggest that RX J0911.4+0551 is a young galaxy in an early stage of its evolution, having experienced no recent major mergers, star formation being concentrated in its centre.

Through a lens darkly: magnified views of massive galaxy formation

“…This velocity o set is probably due to an inaccurate measurement of the systemic velocity obtained from optical spectroscopy. The line pro le has a FWHM of 133 ± 3 km s −1 based on a single Gaussian t, which is similar to the 120 ± 14 km s −1 reported for the CO (7-6) line by Tuan-Anh et al (2017). Imaging of the CO line emission shows compact structure that is similar to the dust continuum (see Fig.…”

“…Magni cations of more than 20 are unlikely if the sources are extended more than ∼ 200 pc, as discussed in the Barvainis & Ivison study. The two sources in our sample with reconstructed dust emission, RX J0911+0551 and the Cloverleaf quasar, both have dust emitting regions of ∼ 1 kpc in size (Tuan-Anh et al 2017;Chapter 4). Assuming these sizes are characteristic, our assumption of µ est.…”

A Multiwavelength Study of ELAN Environments (AMUSE$^2$): Detection of a dusty star-forming galaxy within the enormous Lyman $α$ nebula at $z=2.3$ sheds light on its origin

“…For the CO(3-2) measurements on quasars reported in Hill et al (2019) we adopt a r 31 = 0.97 again based on Carilli & Walter (2013). In addition, we adopt α CO = 1.0 M (K km s −1 pc 2 ) −1 and r e = 3 kpc for SMGs and quasars (Chen et al 2017;Tuan-Anh et al 2017;Calistro Rivera et al 2018;Badole et al 2020;Bischetti et al 2021). Note these adopted values are averages, and each of which comes with a range of uncertainties that are beyond the scope of this paper.…”

VLA and ALMA observations of the lensed radio-quiet quasar SDSS J0924+0219: a molecular structure in a 3 microJy radio source

“…Molecular gas reservoirs have also been found in quasars (Riechers et al 2009a;Tuan-Anh et al 2017;Paraficz et al 2018). We can use lens models to correct for the lensing magnification and derive the intrinsic CO luminosity in these objects, and also estimate the molecular gas mass if we assume the quantity α CO , which relates CO to overall molecular gas mass, is similar to more directly accessible objects ( Venturini & Solomon 2003;Riechers et al 2009a;Riechers et al 2011;Deane et al 2013;Tuan-Anh et al 2017). More recently, detailed imaging together with lens inversion has been used to calculate values for α CO and reconstruct lensed sources in more detail (Paraficz et al 2018;Spingola et al 2019).…”

“…Hezaveh et al 2013b;Rybak et al 2015;Aravena et al 2016;Yang et al 2017;Geach et al 2018). Molecular gas reservoirs have also been found in quasars (Riechers et al 2009a;Tuan-Anh et al 2017;Paraficz et al 2018). We can use lens models to correct for the lensing magnification and derive the intrinsic CO luminosity in these objects, and also estimate the molecular gas mass if we assume the quantity α CO , which relates CO to overall molecular gas mass, is similar to more directly accessible objects ( Venturini & Solomon 2003;Riechers et al 2009a;Riechers et al 2011;Deane et al 2013;Tuan-Anh et al 2017).…”