We present H i synthesis imaging of the giant elliptical galaxy IC 1459 and its surroundings with the Australia Telescope Compact Array (ATCA). Our search for extended H i emission revealed a large complex of H i clouds near IC 1459, likely the debris from tidal interactions with neighbouring galaxies. The total H i mass (∼ 10 9 M ) in the detected clouds spans 250 kpc from the north-east of the gas-rich spiral NGC 7418A to the south-east of IC 1459. The extent and mass of the H i debris, which shows rather irregular morphology and kinematics, are similar to those in other nearby groups. Together with H i clouds recently detected near two other IC 1459 group members, namely IC 5270 and NGC 7418, using Phased-Array Feeds (PAFs) on the Australian Square Kilometer Array Pathfinder (ASKAP), the detected debris make up a significant fraction of the group's intergalactic medium.

The massive binary system WR 11 (γ 2 -Velorum) has been recently proposed as the counterpart of a Fermi source. If this association is correct, this system would be the second colliding wind binary detected in GeV γ-rays. However, the reported flux measurements from 1.4 to 8.64 GHz fail to establish the presence of non-thermal (synchrotron) emission from this source. Moreover, WR 11 is not the only radio source within the Fermi detection box. Other possible counterparts have been identified in archival data, some of which present strong non-thermal radio emission. We conducted arcsec-resolution observations towards WR 11 at very low frequencies (150 to 1400 MHz) where the non-thermal emission -if existent and not absorbed-is expected to dominate, and present a catalog of more than 400 radio-emitters, among which a significant part is detected at more than one frequency, including limited spectral index information. Twenty-one of them are located within the Fermi significant emission. A search for counterparts for this last group pointed at MOST 0808-471, a source 2' away from WR 11, as a promising candidate for high-energy emission, with resolved structure along 325 -1390 MHz. For it, we reprocessed archive interferometric data up to 22.3 GHz and obtained a non-thermal radio spectral index of −0.97 ± 0.09. However, multiwavelength observations of this source are required to establish its nature and to assess whether it can produce (part of) the observed γ-rays. WR 11 spectrum follows a spectral index of 0.74±0.03 from 150 MHz to 230 GHz, consistent with thermal emission. We interpret that any putative synchrotron radiation from the colliding-wind region of this relatively short-period system is absorbed in the photospheres of the individual components. Notwithstanding, the new radio data allowed to derive a mass loss rate of 2.5 × 10 −5 M yr −1 , which, according to the latest models for γ-ray emission in WR 11, would suffice to provide the required kinetic power to feed non-thermal radiation processes.

We present new H i data of the dwarf galaxy KK 69, obtained with the Giant Metrewave Radio Telescope (GMRT) with a signal-to-noise ratio that almost double previous observations. We carried out a Gaussian spectral decomposition and stacking methods to identify the cold neutral medium (CNM) and the warm neutral medium (WNM) of the H i gas. We found that 30% of the total H i gas, which corresponds to a mass of ∼10 7 M , is in the CNM phase. The distribution of the H i in KK 69 is not symmetric. Our GMRT H i intensity map of KK 69 overlaid onto a Hubble Space Telescope image reveals an offset of ∼4 kpc between the H i high-density region and the stellar body, indicating it may be a dwarf transitional galaxy. The offset, along with the potential truncation of the H i body, are evidence of interaction with the central group spiral galaxy NGC 2683, indicating the H i gas is being stripped from KK 69. Additionally, we detected extended H i emission of a dwarf galaxy member of the group as well as a possible new galaxy located near the north-eastern part of the NGC 2683 H i disk.