The Unapologetic Vatican in the Shapley Supercluster

In 1992, the Vatican admitted that Galileo Galilei was right and the Earth is not at the center of the Universe. This was a bit late, 350 years after Galileo died and 33 years after humans landed on…

The SARAO MeerKAT 1.3 GHz Galactic Plane Survey

We present the SARAO MeerKAT Galactic Plane Survey (SMGPS), a 1.3 GHz continuum survey of almost half of the Galactic Plane (251°$\le l \le$ 358°and 2°$\le l \le$ 61°at $|b| \le 1.5°$). SMGPS is the largest, most sensitive and highest angular resolution 1 GHz survey of the Plane yet carried out, with an angular resolution of 8" and a broadband RMS sensitivity of $\sim$10--20 $μ$ Jy/beam. Here we describe the first publicly available data release from SMGPS which comprises data cubes of frequency-resolved images over 908--1656 MHz, power law fits to the images, and broadband zeroth moment integrated intensity images. A thorough assessment of the data quality and guidance for future usage of the data products are given. Finally, we discuss the tremendous potential of SMGPS by showcasing highlights of the Galactic and extragalactic science that it permits. These highlights include the discovery of a new population of non-thermal radio filaments; identification of new candidate supernova remnants, pulsar wind nebulae and planetary nebulae; improved radio/mid-IR classification of rare Luminous Blue Variables and discovery of associated extended radio nebulae; new radio stars identified by Bayesian cross-matching techniques; the realisation that many of the largest radio-quiet WISE HII region candidates are not true HII regions; and a large sample of previously undiscovered background HI galaxies in the Zone of Avoidance.

HI Galaxy Signatures in the SARAO MeerKAT Galactic Plane Survey -- II. The Local Void and its substructure

The Local Void is one of the nearest large voids, located at a distance of 23 Mpc. It lies largely behind the Galactic Bulge and is therefore extremely difficult to observe. We use HI 21 cm emission observations from the SARAO MeerKAT Galactic Plane Survey (SMGPS) to study the Local Void and its surroundings over the Galactic longitude range 329$^{\circ}< \ell <$ 55$^{\circ}$, Galactic latitude $|b| <$ 1.5$^{\circ}$, and redshift $cz <$ 7500 km/s. We have detected 291 galaxies to median rms sensitivity of 0.44 mJy per beam per 44 km/s channel. We find 17 galaxies deep inside the Void, 96 at the border of the Void, while the remaining 178 galaxies are in average density environments. The extent of the Void is ~ 58 Mpc. It is severely under-dense for the longitude range 350$^{\circ}< \ell <$ 35$^{\circ}$ up to redshift $z <$ 4500 km/s. The galaxies in the Void tend to have \HI masses that are lower (by approximately 0.25 dex) than their average density counterparts. We find several potential candidates for small groups of galaxies, of which two groups (with 3 members and 5 members) in the Void show signs of filamentary substructure within the Void.

HI Galaxy Signatures in the SARAO MeerKAT Galactic Plane Survey $-$ I. Probing the richness of the Great Attractor Wall across the inner Zone of Avoidance

This paper presents the first HI results extracted from the SARAO MeerKAT Galactic Plane Survey (SMGPS) $-$ a narrow strip ($b \sim 3^\circ$) along the southern Milky Way. The primary goal consisted in tracing the Great Attractor (GA) Wall across the innermost Zone of Avoidance. We reduced a segment spanning the longitude range $302^\circ \leq \ell \leq 332^\circ$ for the redshift range $z \leq 0.08$. The superb SMGPS sensitivity (rms = 0.3-0.5 mJy beam$^{-1}$ per 44 kms$^{-1}$ channel) and angular resolution ($\sim$ 31" $\times$ 26") lead to a detection limit of log$(M_{\rm HI}/$M$_\odot) \geq$ 8.5 at the GA distance ($V_{\rm hel} \sim 3500 - 6500$ kms$^{-1}$). A total of 477 galaxy candidates were identified over the full redshift range. A comparison of the few HI detections with counterparts in the literature (mostly HIZOA) found the HI fluxes and other HI parameters to be highly consistent. The continuation of the GA Wall is confirmed through a prominent overdensity of $N = 214$ detections in the GA distance range. At higher latitudes, the wall moves to higher redshifts, supportive of a possible link with the Ophiuchus cluster located behind the Galactic Bulge. This deep interferometric HI survey demonstrates the power of the SMGPS in improving our insight of large-scale structures at these extremely low latitudes, despite the high obscuration and continuum background.

Scientists discover massive 'extragalactic structure' behind the Milky Way

An uncharted region of space known as the "zone of avoidance" lurks behind the Milky Way's center – and astronomers just found an enormous, multi-galaxy structure there.

Scientists discover massive 'extragalactic structure' behind the Milky Way

An uncharted region of space known as the "zone of avoidance" lurks behind the Milky Way's center – and astronomers just found an enormous, multi-galaxy structure there.

Writer Fuel: Scientists Find Enormous Cluster of Galaxies Hidden in the “Zone of Avoidance”

Astronomers have detected an enormous extragalactic structure hiding in an uncharted region of space far beyond the Milky Way's center. This phantom region, known as the zone of avoidance, is a blank spot on our map of the universe, comprising somewhere between 10% and 20% of the night sky. The reason we can't see it...

Writer Fuel: Scientists Find Enormous Cluster of Galaxies Hidden in the “Zone of Avoidance”

Astronomers have detected an enormous extragalactic structure hiding in an uncharted region of space far beyond the Milky Way's center. This phantom region, known as the zone of avoidance, is a blank spot on our map of the universe, comprising somewhere between 10% and 20% of the night sky. The reason we can't see it...

Extended Data Figure 3: One of three orthogonal views that illustrate the limits of the Laniakea supercluster. | Nature