| 1. |
- Muxlow, T. W. B., et al.
(author)
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The e-MERGE Survey (e-MERLIN Galaxy Evolution Survey): overview and survey description
- 2020
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In: Monthly Notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 495:1, s. 1188-1208
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Journal article (peer-reviewed)abstract
- We present an overview and description of the e-MERGE Survey (e-MERLIN Galaxy Evolution Survey) Data Release 1 (DR1), a large program of high-resolution 1.5-GHz radio observations of the GOODS-N field comprising similar to 140 h of observations with enhanced-Multi-Element Remotely Linked Interferometer Network (e-MERLIN) and similar to 40 h with the Very Large Array (VLA). We combine the long baselines of e-MERLIN (providing high angular resolution) with the relatively closely packed antennas of the VLA (providing excellent surface brightness sensitivity) to produce a deep 1.5-GHz radio survey with the sensitivity (similar to 1.5 mu Jy beam(-1)), angular resolution (0.2-0.7 arcsec) and field-of-view (similar to 15x15 arcmin(2)) to detect and spatially resolve star-forming galaxies and active galactic nucleus (AGN) at z greater than or similar to 1. The goal of e-MERGE is to provide new constraints on the deep, sub-arcsecond radio sky which will be surveyed by SKA1-mid. In this initial publication, we discuss our data analysis techniques, including steps taken to model in-beam source variability over an similar to 20-yr baseline and the development of newpoint spread function/primary beam models to seamlessly merge e-MERLIN and VLA data in the uv plane. We present early science results, including measurements of the luminosities and/or linear sizes of similar to 500 galaxies selected at 1.5 GHz. In combination with deep Hubble Space Telescope observations, we measure a mean radio-to-optical size ratio of r(e-MERGE)/r(HST) similar to 1.02 +/- 0.03, suggesting that in most high-redshift galaxies, the similar to GHz continuum emission traces the stellar light seen in optical imaging. This is the first in a series of papers that will explore the similar to kpc-scale radio properties of star-forming galaxies and AGN in the GOODS-N field observed by e-MERGE DR1.
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| 2. |
- Deane, R. P., et al.
(author)
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The VLBA CANDELS GOODS-North Survey -I. survey design, processing, data products, and source counts
- 2024
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In: Monthly Notices of the Royal Astronomical Society. - 0035-8711 .- 1365-2966. ; 529:3, s. 2428-2442
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Journal article (peer-reviewed)abstract
- The past decade has seen significant advances in wide-field cm-wave very long baseline interferometry (VLBI), which is timely given the wide-area, synoptic survey-driven strategy of major facilities across the electromagnetic spectrum. While wide-field VLBI poses significant post-processing challenges that can severely curtail its potential scientific yield, man y dev elopments in the km-scale connected-element interferometer sphere are directly applicable to addressing these. Here we present the design, processing, data products, and source counts from a deep (11 μJy beam -1 ), quasi-uniform sensitivity, contiguous wide-field (160 arcmin 2 ) 1.6 GHz VLBI surv e y of the CANDELS GOODS-North field. This is one of the best-studied extragalactic fields at milli-arcsecond resolution and, therefore, is well-suited as a comparative study for our Tera-pixel VLBI image. The derived VLBI source counts show consistency with those measured in the COSMOS field, which broadly traces the AGN population detected in arcsecond-scale radio surv e ys. Ho we ver, there is a distinctive flattening in the S 1.4GHz ∼100-500 μJy flux density range, which suggests a transition in the population of compact faint radio sources, qualitatively consistent with the excess source counts at 15 GHz that is argued to be an unmodelled population of radio cores. This surv e y approach will assist in deriving robust VLBI source counts and broadening the disco v ery space for future wide-field VLBI surv e ys, including VLBI with the Square Kilometre Array, which will include new large field-of-view antennas on the African continent at ≲1000 km baselines. In addition, it may be useful in the design of both monitoring and/or rapidly triggered VLBI transient programmes.
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| 3. |
- Orosz, G., et al.
(author)
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Bow shocks in water fountain jets
- 2017
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In: Proceedings of the International Astronomical Union. - 1743-9213 .- 1743-9221. ; 13:S336, s. 351-354
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Conference paper (peer-reviewed)abstract
- We briefly introduce the VLBI maser astrometric analysis of IRAS 18043-2116 and IRAS 18113-2503, two remarkable and unusual water fountains with spectacular bipolar bow shocks in their high-speed collimated jet-driven outflows. The 22 GHz H2O maser structures and velocities clearly show that the jets are formed in very short-lived, episodic outbursts, which may indicate episodic accretion in an underlying binary system.
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