H. J. Farnhill
University of Hertfordshire
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Monthly Notices of the Royal Astronomical Society | 2014
Janet E. Drew; E. Gonzalez-Solares; R. Greimel; M. J. Irwin; A. Küpcü Yoldas; J. Lewis; G. Barentsen; J. Eislöffel; H. J. Farnhill; W. Martin; Jeremy R. Walsh; N. A. Walton; M. Mohr-Smith; R. Raddi; S. E. Sale; N. J. Wright; Paul J. De Groot; Michael J. Barlow; Romano L. M. Corradi; Jeremy J. Drake; Juan Fabregat; David J. Frew; B. T. Gänsicke; Christian Knigge; A. Mampaso; Rhys Morris; T. Naylor; Quentin A. Parker; Steven Phillipps; C. Ruhland
The VST Photometric HSurvey of the Southern Galactic Plane and Bulge (VPHAS+) is surveying the southern Milky Way in u,g,r,i and Hat �1 arcsec angular resolution. Its footprint spans the Galactic latitude range 5 o < b < +5 o at all longitudes south of the celestial equator. Extensions around the Galactic Centre to Galactic latitudes ±10 ◦ bring in much of the Galactic Bulge. This ESO public sur- vey, begun on 28th December 2011, reaches down to �20th magnitude (10�) and will provide single-epoch digital optical photometry for �300 million stars. The observing strategy and data pipelining is described, and an appraisal of the segmented narrow- band Hfilter in use is presented. Using model atmospheres and library spectra, we compute main-sequence (u g), (g r), (r i) and (r H�) stellar colours in the Vega system. We report on a preliminary validation of the photometry using test data obtained from two pointings overlapping the Sloan Digital Sky Survey. An example of the (u g,g r) and (r H�,r i) diagrams for a full VPHAS+ survey field is given. Attention is drawn to the opportunities for studies of compact nebulae and nebular morphologies that arise from the image quality being achieved. The value of the u band as the means to identify planetary-nebula central stars is demonstrated by the discovery of the central star of NGC 2899 in survey data. Thanks to its excellent imaging performance, the VST/OmegaCam combination used by this survey is a per- fect vehicle for automated searches for reddened early-type stars, and will allow the discovery and analysis of compact binaries, white dwarfs and transient sources.
Monthly Notices of the Royal Astronomical Society | 2014
G. Barentsen; H. J. Farnhill; Janet E. Drew; E. Gonzalez-Solares; R. Greimel; M. J. Irwin; Brent Miszalski; C. Ruhland; P. Groot; A. Mampaso; S. E. Sale; A.A. Henden; A. Aungwerojwit; M. J. Barlow; P.R. Carter; Romano L. M. Corradi; Jeremy J. Drake; J. Eislöffel; J. Fabregat; B. T. Gänsicke; N. P. Gentile Fusillo; A. Hales; Simon T. Hodgkin; Leo Huckvale; J. Irwin; Robert R. King; Christian Knigge; T. Kupfer; E. Lagadec; Daniel J. Lennon
The INT/WFC Photometric Hα Survey of the Northern Galactic Plane (IPHAS) is a 1800 deg2 imaging survey covering Galactic latitudes |b| < 5° and longitudes l = 30°–215° in the r, i, and Hα filters using the Wide Field Camera (WFC) on the 2.5-m Isaac Newton Telescope (INT) in La Palma. We present the first quality-controlled and globally calibrated source catalogue derived from the survey, providing single-epoch photometry for 219 million unique sources across 92 per cent of the footprint. The observations were carried out between 2003 and 2012 at a median seeing of 1.1 arcsec (sampled at 0.33 arcsec pixel−1) and to a mean 5σ depth of 21.2 (r), 20.0 (i), and 20.3 (Hα) in the Vega magnitude system. We explain the data reduction and quality control procedures, describe and test the global re-calibration, and detail the construction of the new catalogue. We show that the new calibration is accurate to 0.03 mag (root mean square) and recommend a series of quality criteria to select accurate data from the catalogue. Finally, we demonstrate the ability of the catalogues unique (r − Hα, r − i) diagram to (i) characterize stellar populations and extinction regimes towards different Galactic sightlines and (ii) select and quantify Hα emission-line objects. IPHAS is the first survey to offer comprehensive CCD photometry of point sources across the Galactic plane at visible wavelengths, providing the much-needed counterpart to recent infrared surveys.
The Astronomical Journal | 2012
D. Steeghs; B. T. Gänsicke; E. L. Martín; P. Groot; M. J. Irwin; E. Gonzalez-Solares; R. Greimel; Christian Knigge; Roy Ostensen; Kars Verbeek; Janet E. Drew; Jeremy J. Drake; P. G. Jonker; V. Ripepi; S. Scaringi; J. Southworth; Martin Still; N. J. Wright; H. J. Farnhill; L.M. van Haaften; S. Shah
This paper describes the first data release of the Kepler-INT Survey (KIS), that covers a 116 deg2 region of the Cygnus and Lyra constellations. The Kepler field is the target of the most intensive search for transiting planets to date. Despite the fact that the Kepler mission provides superior time series photometry, with an enormous impact on all areas of stellar variability, its field lacks optical photometry complete to the confusion limit of the Kepler instrument necessary for selecting various classes of targets. For this reason, we follow the observing strategy and data reduction method used in the IPHAS and UVEX galactic plane surveys in order to produce a deep optical survey of the Kepler field. This initial release concerns data taken between May and August 2011, using the Isaac Newton Telescope on the island of La Palma. Four broadband filters were used, U, g, r, i, as well as one narrowband one, Halpha, reaching down to a 10-sigma limit of around 20th mag in the Vega system. Observations covering around 50 deg2, thus about half of the field, passed our quality control thresholds and constitute this first data release. We derive a global photometric calibration by placing the KIS magnitudes as close as possible to the Kepler Input Catalog (KIC) photometry. The initial data release catalogue containing around 6 million sources from all the good photometric fields is available for download from the KIS webpage, as well as via MAST.
Monthly Notices of the Royal Astronomical Society | 2014
S. E. Sale; Janet E. Drew; G. Barentsen; H. J. Farnhill; R. Raddi; M. J. Barlow; J. Eislöffel; Jorick S. Vink; P. Rodríguez-Gil; N. J. Wright
We present a three dimensional map of extinction in the Northern Galactic Plane derived using photometry from the IPHAS survey. The map has fine angular ( 10 0 ) and distance (100 pc) sampling allied to a significant depth (& 5 kpc). We construct the map using a method based on a hierarchical Bayesian model as previously described by Sale (2012). In addition to mean extinction, we also measure differential extinction, which arises from the fractal nature of the ISM, and show that it will be the dominant source of uncertainty in estimates of extinction to some arbitrary position. The method applied also furnishes us with photometric estimates of the distance, extinction, effective temperature, surface gravity, and mass for 38 million stars. Both the extinction map and the catalogue of stellar parameters are made publicly available via http://www.iphas.org/extinction.
Monthly Notices of the Royal Astronomical Society | 2016
R. Raddi; S. Catalán; B. T. Gänsicke; J. J. Hermes; Ralf Napiwotzki; D. Koester; P.-E. Tremblay; G. Barentsen; H. J. Farnhill; M. Mohr-Smith; Janet E. Drew; P. Groot; L. Guzman-Ramirez; Quentin A. Parker; D. Steeghs; Albert A. Zijlstra
We investigated the prospects for systematic searches of white dwarfs at low Galactic latitudes, using the VLT Survey Telescope (VST) H
Monthly Notices of the Royal Astronomical Society | 2014
N. J. Wright; R. Wesson; Janet E. Drew; G. Barentsen; Michael J. Barlow; Jeremy R. Walsh; Albert A. Zijlstra; Jeremy J. Drake; J. Eislöffel; H. J. Farnhill
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Monthly Notices of the Royal Astronomical Society | 2013
R. Raddi; Janet E. Drew; J. Fabregat; D. Steeghs; N. J. Wright; S. E. Sale; H. J. Farnhill; M. J. Barlow; R. Greimel; L. Sabin; R. M. L. Corradi; Jeremy J. Drake
Photometric Survey of the Galactic plane and Bulge (VPHAS+). We targeted 17 white dwarf candidates along sightlines of known open clusters, aiming to identify potential cluster members. We confirmed all the 17 white dwarf candidates from blue/optical spectroscopy, and we suggest five of them to be likely cluster members. We estimated progenitor ages and masses for the candidate cluster members, and compared our findings to those for other cluster white dwarfs. A white dwarf in NGC 3532 is the most massive known cluster member (1.13 M
Monthly Notices of the Royal Astronomical Society | 2017
M. Mohr-Smith; Janet E. Drew; R. Napiwotzki; S. Simón-Díaz; N. J. Wright; G. Barentsen; J. Eislöffel; H. J. Farnhill; R. Greimel; M. Monguió; Venu M. Kalari; Q. A. Parker; Jorick S. Vink
_{\odot}
Monthly Notices of the Royal Astronomical Society | 2016
H. J. Farnhill; Janet E. Drew; G. Barentsen; E. Gonzalez-Solares
), likely with an oxygen-neon core, for which we estimate an
Monthly Notices of the Royal Astronomical Society | 2018
A. Harris; Janet E. Drew; H. J. Farnhill; M. Monguió; M. Gebran; N. J. Wright; Jeremy J. Drake; S. E. Sale
8.8_{-4.3}^{+1.2}