The INT Photometric Hα Survey of the Northern Galactic Plane (IPHAS) (original) (raw)
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The INT Photometric H Survey of the Northern Galactic Plane (IPHAS)
Monthly Notices of the Royal Astronomical Society, 2005
The INT Photometric Hα Survey of the Northern Galactic Plane (IPHAS) is a 1800 square degrees CCD survey of the northern Milky Way spanning the latitude range −5 o < b < +5 o and reaching down to r ′ ≃ 20 (10σ). It may increase the number of known northern emission line sources by an order of magnitude. Representative observations and an assessment of point-source data from IPHAS, now underway, are presented. The data obtained are Wide Field Camera images in Hα alpha narrow-band, and Sloan r ′ and i ′ broad-band, filters. We simulate IPHAS (r ′ − Hα, r ′ − i ′ ) pointsource colours using a spectrophotometric library of stellar spectra and available filter transmission profiles: this gives expected colours for (i) solar-metallicity stars, without Hα emission, and (ii) emission line stars. Comparisons with Aquila field observations show that simulated normal star colours reproduce the data well for spectral types earlier than M. Spectroscopic follow-up of a Cepheus field confirms that sources lying above the main stellar locus in the (r ′ − Hα, r ′ − i ′ ) plane are emission line objects, with very few failures. Examples of Hα deficit objects -a white dwarf and a carbon star -are shown to be readily distinguished by their IPHAS colours. The role IPHAS can play in studies of nebulae is discussed briefly, and illustrated by a continuumsubtracted mosaic image of the SNR, Shajn 147. The final catalogue of IPHAS point sources will contain photometry on about 80 million objects. (abridged for astro-ph))
Submitted to The Astronomical Journal
1996
This paper presents Australia Telescope Compact Array H I synthesis observations of the weak blue compact dwarf (BCD) galaxy NGC 2915. It is shown that NGC 2915 has the H I properties of a late type spiral galaxy (Sd- Sm), including a double horn global profile, and H I spiral arms. The H I extends out to over five times the Holmberg radius, and 22 times the exponential scale length in the B band. The optical counterpart corresponds to a central H I bar. The H I distribution and kinematics are discussed in detail. A rotation curve is derived and fitted with a mass model consisting of a stellar disk, a neutral gas disk, and a dark matter (DM) halo. The DM halo dominates at nearly all radii. The total mass to blue light ratio, MT/LB = 76 within the last measured point. Thus NGC 2915 is one of the darkest disk galaxies known. The complex H I dynamics of the central region results in a high uncertainty of many of the fitted 1 parameters. Nevertheless it is clear that the core of the DM ...
2000
Abstract. Atmospheric parameters (Teff, log g), and radial velocities are derived for twelve candidate blue horizontal branch (HB) stars in the globular clusters 47 Tuc and NGC 362, which so far have been known to contain primarily red HB stars. The spectroscopic targets were selected from the catalog of hot stars detected in these clusters at 1600 ˚A using the Ultraviolet Imaging Telescope (UIT). Spectroscopic analyses of these stars reveal, however, that one of the four HB candidates targets in 47 Tuc, and five out of the eight targets in NGC 362 are probably background stars belonging to the Small Magellanic Cloud. With the exception of the photometric binary MJ38529 in 47 Tuc, the parameters of those stars that are probable members of 47 Tuc and NGC 362 agree well with canonical HB evolution. The three hot stars in 47 Tuc all have 10,000 K < Teff < 15,000 K and include one photometric binary, which suggests that they might have a different physical origin than the dominant...
Submitted to the Astrophysical Journal
2005
Analysis of broadband HST ACS and WFPC2 images of the young Galactic supernova remnant Cassiopeia A reveals a far larger population of outlying, high-velocity knots of ejecta with a broader range of chemical properties than previously suspected. ACS filter flux ratios along with follow-up, ground-based spectra are used to investigate some of the kinematic and chemical properties of these outermost ejecta. In this paper, we concentrate on a ≃1.5 sq arcmin region located along the eastern limb of the remnant where numerous outer emission knots are optically visible due to an interaction with a local circumstellar cloud, thereby providing a more complete and unbiased look at the remnant’s fastest debris fragments. From a study of this region, we identify three main classes of outer ejecta: 1) Knots dominated by [N II] λλ6548,6583 emission; 2) Knots dominated by oxygen emission lines especially [O II] λλ7319,7330; and 3) Knots with emission line strengths similar to the [S II] strong FM...
1997
IUE high-resolution observations of the symbiotic star CH Cygni: confirmation of the triple-star model ⋆
Initial data release from the INT Photometric Hα Survey of the Northern Galactic Plane (IPHAS)
Monthly Notices of …, 2008
The INT/WFC Photometric Hα Survey of the Northern Galactic Plane (IPHAS) is an imaging survey being carried out in Hα, r ′ and i ′ filters, with the Wide Field Camera (WFC) on the 2.5-metre Isaac Newton Telescope (INT) to a depth of r ′ =20 (10σ). The survey is aimed at revealing the large scale organisation of the Milky Way and can be applied to identifying a range of stellar populations within it. Mapping emission line objects enables a particular focus on objects in the young and old stages of stellar evolution ranging from early T-Tauri stars to late planetary nebulae. In this paper we present the IPHAS Initial Data Release, primarily a photometric catalogue of about 200 million unique objects, coupled with associated image data covering about 1,600 square degrees in three passbands. We note how access to the primary data products has been implemented through use of standard virtual observatory publishing interfaces. Simple traditional web access is provided to the main IPHAS photometric catalogue, in addition to a number of common catalogues (such as 2MASS) which are of immediate relevance. Access through the AstroGrid VO Desktop opens up the full range of analysis options, and allows full integration with the wider range of data and services available through the Virtual Observatory. The IDR represents the c 2008 RAS
The second data release of the INT Photometric Hα Survey of the Northern Galactic Plane (IPHAS DR2)
Monthly Notices of the Royal Astronomical Society, 2014
The INT/WFC Photometric Hα Survey of the Northern Galactic Plane (IPHAS) is a 1800 deg 2 imaging survey covering Galactic latitudes |b| < 5 • and longitudes = 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 catalogue's 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 UKIDSS Galactic Plane Survey
Monthly Notices of the Royal Astronomical Society, 2008
The UKIDSS Galactic Plane Survey (GPS) is one of the five near infrared Public Legacy Surveys that are being undertaken by the UKIDSS consortium, using the Wide Field Camera on the United Kingdom Infrared Telescope. It is surveying 1868 deg 2 of the northern and equatorial Galactic plane at Galactic latitudes −5 • < b < 5 • in the J, H and K filters and a ∼ 200 deg 2 area of the Taurus-Auriga-Perseus molecular cloud complex in these three filters and the 2.12 µm (1-0) H 2 filter. It will provide data on ∼ 2 × 10 9 sources. Here we describe the properties of the dataset and provide a user's guide for its exploitation. We also present brief Demonstration Science results from DR2 and from the Science Verification programme. These results illustrate how GPS data will frequently be combined with data taken in other wavebands to produce scientific results. The Demonstration Science comprises six studies. (1) A GPS-Spitzer-GLIMPSE cross match for the star formation region G28.983-0.603 to identify YSOs. This increases the number of YSOs identified by a factor of ten compared to GLIMPSE alone. (2) A wide field study of the M17 nebula, in which an extinction map of the field is presented and the effect of source confusion on luminosity functions in different sub-regions is noted. (3) H 2 emission in the ρ Ophiuchi dark cloud. All the molecular jets are traced back to a single active clump containing only a few protostars, which suggests that the duration of strong jet activity and associated rapid accretion in low mass protostars is brief. (4) X-ray sources in the Nuclear Bulge. The GPS data distinguishes local main sequence counterparts with soft X-ray spectra from Nuclear Bulge giant counterparts with hard X-ray spectra. (5) External galaxies in the Zone of Avoidance. The galaxies are clearly distinguished from stars in fields at longitudes l>90 • . (6) IPHAS-GPS optical-infrared spectrophotometric typing. The (i'-J) vs.(J-H) diagram is used to distinguish A-F type dwarfs, G dwarfs, K dwarfs and red clump giants in a field with high reddening.