New young planetary nebulae in IPHAS (original) (raw)
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Candidate planetary nebulae in the IPHAS photometric catalogue
Astronomy and Astrophysics, 2009
Context. We have carried out a semi-automated search for planetary nebulae (PNe) in the INT photometric H-alpha survey (IPHAS) catalogue. We present the PN search and the list of selected candidates. We cross correlate the selected candidates with a number of existing infrared galactic surveys in order to gain further insight into the nature of the candidates. Spectroscopy of a subset of objects is used to estimate the number of PNe present in the entire candidate list. Aims. The overall aim of the IPHAS PN project is to carry out a deep census of PNe in the northern Galactic plane, an area where PN detections are clearly lacking. Methods. The PN search is carried out on the IPHAS photometric catalogue. The candidate selection is based on the IPHAS and 2MASS/UKIDSS colours of the objects and the final candidate selection is made visually. Results. From the original list of ∼600 million IPHAS detections we have selected a total of 1005 objects. Of these, 224 are known objects, leaving us with 781 PN candidates. Based on the initial follow-up spectroscopy, we expect the list to include very young and proto-PNe in addition to genuine, normal PNe (∼16%) and emission line objects other than PNe. We present additional criteria to select the most probable PN candidates from our candidate list.
c © ESO 2009 Astronomy &Astrophysics Candidate planetary nebulae in the IPHAS photometric catalogue
2009
Context. We have carried out a semi-automated search for planetary nebulae (PNe) in the INT photometric H-alpha survey (IPHAS) catalogue. We present the PN search and the list of selected candidates. We cross correlate the selected candidates with a number of existing infrared galactic surveys in order to gain further insight into the nature of the candidates. Spectroscopy of a subset of objects is used to estimate the number of PNe present in the entire candidate list. Aims. The overall aim of the IPHAS PN project is to carry out a deep census of PNe in the northern Galactic plane, an area where PN detections are clearly lacking. Methods. The PN search is carried out on the IPHAS photometric catalogue. The candidate selection is based on the IPHAS and 2MASS/UKIDSS colours of the objects and the final candidate selection is made visually. Results. From the original list of ∼600 million IPHAS detections we have selected a total of 1005 objects. Of these, 224 are known objects, leavin...
First release of the IPHAS catalogue of new extended planetary nebulae
Monthly Notices of the Royal Astronomical Society, 2014
We present the first results of our search for new, extended Planetary Nebulae (PNe) based on careful, systematic, visual scrutiny of the imaging data from the INT Photometric Hα Survey of the Northern Galactic Plane (IPHAS). The newly uncovered PNe will help to improve the census of this important population of Galactic objects that serve as key windows into the late stage evolution of low to intermediate mass stars. They will also facilitate study of the faint end of the ensemble Galactic PN luminosity function. The sensitivity and coverage of IPHAS allows PNe to be found in regions of greater extinction in the Galactic Plane and/or those PNe in a more advanced evolutionary state and at larger distances compared to the general Galactic PN population. Using a set of newly revised optical diagnostic diagrams in combination with access to a powerful, new, multi-wavelength imaging database, we have identified 159 true, likely and possible PNe for this first catalogue release. The ability of IPHAS to unveil PNe at low Galactic latitudes and towards the Galactic Anticenter, compared to previous surveys, makes this survey an ideal tool to contribute to the improvement of our knowledge of the whole Galactic PN population.
HASH: the Hong Kong/AAO/Strasbourg Hα planetary nebula database
By incorporating our major recent discoveries with re-measured and verified contents of existing catalogues we provide, for the first time, an accessible, reliable, on-line SQL database for essential, up-to date information for all known Galactic planetary nebulae (PNe). We have attempted to: i) reliably remove PN mimics/false ID's that have biased previous studies and ii) provide accurate positions, sizes, morphologies, multi-wavelength imagery and spectroscopy. We also provide a link to CDS/Vizier for the archival history of each object and other valuable links to external data. With the HASH interface, users can sift, select, browse, collate, investigate, download and visualise the entire currently known Galactic PNe diversity. HASH provides the community with the most complete and reliable data with which to undertake new science. 1. Introduction PNe, the ejected, ionised shrouds of dying stars, are a complex and brief (∼25,000 year) phase of late stellar evolution. They offer rich science as vital probes of stellar nucleosynthesis processes in mid to low-mass stars. These stars make-up 90% of all stars above 1 solar mass. They provide a detectable, fossil record of stellar mass loss off the AGB/post-AGB and are powerful tracers of our Galaxy's star-forming history. Furthermore, they are useful kinematical probes visible to large Galactic distances due to their rich, strong, emission line spectra. These scientific levers and others encourage the search for and study of PN in our own and other Galaxies. We are currently in a golden age of PN discovery. New high sensitivity, wide-field, narrow-band, Galactic plane surveys undertaken on the UK Schmidt Telescope in Australia [1][2], the Isaac Newton telescope on La Palma [3] and now the ESO/VST in Chile [4] have facilitated this. These Hα surveys have provided significant Galactic PNe discoveries that have more than doubled the totals accumulated by all telescopes over the previous 260 years, e.g. [5][6][7][8] and these proceedings, including posters by Kronberger et al. and Acker et al. Most new PNe found are more redenned, evolved and of lower surface brightness than previous compilations such as [9][10] and [11] while others are faint but compact and more distant. The scope of any future large-scale PNe studies, particularly those of a statistical nature or undertaken to understand true PNe diversity and evolution, should now reflect this fresh PN population landscape. Studies should make us of the combined sample of ∼3500 Galactic PNe now available in our HASH database. HASH takes into account recent major discoveries and the power invested in the wide-field, high sensitivity, high resolution, multi-wavelength imaging surveys now available across much of the electromagnetic spectrum.
A search for very young Planetary Nebulae
Astronomy and Astrophysics, 2004
Despite numerous efforts, the transition from Asymptotic Giant Branch (AGB) stars to Planetary Nebulae (PN) is a poorly understood phase of stellar evolution. We have therefore carried out interferometric (VLA) radio observations of a sample of hot post-AGB stars, selected on the basis of their optical and infrared properties. Ten sources out of the 16 observed were detected. This indicates that most of our targets are surrounded by a nebula where the ionization has already started. This definitively determines the evolutionary status of the selected sources and provides us with a unique sample of very young Planetary Nebulae (yPNe). A comparison with another sample of yPNe confirms our working hypothesis that our targets are indeed very young, probably just in the transition toward PN. Finding transition objects is extremely important as they can provide unique clues for a better understanding of this important phase of stellar evolution.
Spectroscopy and imaging of newly discovered planetary nebulae
Astronomy and Astrophysics Supplement Series, 1996
The major purpose of this paper was to prove or disprove the nature of planetary nebula (PN) candidates in the northern hemisphere, taken from an internal list. We present spectroscopic observations and imaging of fifteen PNe, twelve of them identified for the first time. Another two candidates turned out to be an emission-line galaxy and an H ii region. All observed PNe represent evolved stages, their angular diameter ranging from 8 to 90 , and exhibit very low surface brightnesses. The three largest and faintest nebulae each host a central star of magnitude 18 to 20 m .
Publications of the Astronomical Society of Australia, 2010
We present the results of the search for candidate Planetary Nebulae interacting with the interstellar medium (PN–ISM) in the framework of the INT Photometric Hα Survey (IPHAS) and located in the right ascension range 18–20 h. The detection capability of this new Northern survey, in terms of depth and imaging resolution, has allowed us to overcome the detection problem generally associated to the low surface brightness inherent to PNe-ISM. We discuss the detection of 21 IPHAS PN–ISM candidates. Thus, different stages of interaction were observed, implying various morphologies i.e. from the unaffected to totally disrupted shapes. The majority of the sources belong to the so-called WZO2 stage which main characteristic is a brightening of the nebula's shell in the direction of motion. The new findings are encouraging as they would be a first step into the reduction of the scarcity of observational data and they would provide new insights into the physical processes occurring in the...