1. H i galaxy signatures in the SARAO MeerKAT Galactic Plane Survey – I. Probing the richness of the great attractor wall across the inner zone of avoidance.
- Author
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Steyn, Nadia, Kraan-Korteweg, Renée C, Rajohnson, Sambatriniaina H A, Kurapati, Sushma, Chen, Hao, Frank, Bradley, Serra, Paolo, Staveley-Smith, Lister, Camilo, Fernando, and Goedhart, Sharmila
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GALACTIC bulges , *MEERKAT , *MILKY Way , *GALAXIES , *RADIO astronomy - Abstract
This paper presents the first H i results extracted from the South African Radio Astronomy Observatory (SARAO) MeerKAT Galactic Plane Survey (SMGPS) – a narrow strip (Δ b ∼ 3°) 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° ≤ ℓ ≤ 332° for the redshift range z ≤ 0.08. The superb SMGPS sensitivity (rms = 0.3–0.5 mJy beam−1 per 44 km s−1 channel) and angular resolution (∼31″ × 26″) lead to a detection limit of log(M H i /M⊙) ≥ 8.5 at the GA distance (|$\mbox{$V_{\rm {hel}}$}\, \sim 3500{\!-\!}6500$| km s−1). A total of 477 galaxy candidates were identified over the full redshift range. A comparison of the few H i detections with counterparts in the literature (mostly HIZOA) found the H i fluxes and other H i 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 H i 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. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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