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We present neutral hydrogen (H  i) absorption spectra of the black hole candidate X-ray binary (XRB) MAXI J1348–630 using the Australian Square Kilometre Array Pathfinder (ASKAP) and MeerKAT. The ASKAP H  i spectrum shows a maximum negative radial velocity (with respect to the local standard of rest) of −31 ± 4 km s−1 for MAXI J1348–630, as compared to −50 ± 4 km s−1 for a stacked spectrum of several nearby extragalactic sources. This implies a most probable distance of |$2.2^{+0.5}_{-0.6}$|  kpc for MAXI J1348–630, and a strong upper limit of the tangent point distance at 5.3 ± 0.1 kpc. Our preferred distance implies that MAXI J1348–630 reached 17 ± 10  per cent of the Eddington luminosity at the peak of its outburst, and that the source transited from the soft to the hard X-ray spectral state at 2.5 ± 1.5  per cent of the Eddington luminosity. The MeerKAT H  i spectrum of MAXI J1348–630 (obtained from the older, low-resolution 4k mode) is consistent with the re-binned ASKAP spectrum, highlighting the potential of the eventual capabilities of MeerKAT for XRB spectral line studies. [ABSTRACT FROM AUTHOR]

We present the results of a mini-survey for associated H 21-cm absorption at z≤ 0.42 with the Giant Metrewave Radio Telescope. Our targets are radio galaxies, selected on the basis that the λ≈ 1216 Å luminosities are below L∼ 10 W Hz, above which there has never been a detection of 21-cm absorption. Of the three sources for which we obtained good data, two are unclassified active galactic nuclei (AGNs) and one is type-2. Being a non-detection, the type-2 object is consistent with our previous result that 21-cm absorption in radio sources is not dictated by unified schemes of AGN. In the case of the detection, the absorption only occurs towards one of the two resolved radio lobes in PKS 1649-062. If the absorption is due to another intervening galaxy, or cool H gas in the intergalactic medium, covering only the south-west (SW) lobe, then, being at the same redshift, this is likely to be gravitationally bound to the optical object identified as PKS 1649-062. If the absorption is due to an inclined disc centred between the lobes, intervening the SW lobe while being located behind the north-east (NE) lobe, by assuming that it covers the emission peak at ≈150 kpc from the nucleus, we estimate a dynamical mass of ≈3 × 10 M for the disc. [ABSTRACT FROM AUTHOR]

We report the detection of the third H 21-cm absorber in the sight-line towards the quasar MG J0414+0534 (4C +05.19). In addition to the absorption at the host redshift and in the gravitational lens, we find, through a decimetre-wave spectral scan towards this source, strong absorption at . We believe this may be associated with 'Object X', an additional feature apparent in the field of the lensing galaxy and lensed images, on the basis of its close proximity to the quasar images and the possible detection of the [O ] doublet in a published optical spectrum. If real, the strength of the [O ] emission would suggest the presence of an active galactic nucleus, or a gas-rich galaxy undergoing rapid star formation, either of which is consistent with the strong outflows apparent in the 21-cm spectrum. Although this is the strongest intervening 21-cm absorber found to date (a column density of , for a modest ), simultaneous observations failed to detect any of the 18-cm OH lines at the 21-cm redshift. This suggests that, as for the lensing galaxy, this is not the primary location of the intervening material responsible for the very red colour of MG J0414+0534. [ABSTRACT FROM AUTHOR]