- ID:
- ivo://astron.nl/apertif_dr1/q/apertif_dr1_catalogue
- Title:
- Apertif DR1 - Source catalogue
- Short Name:
- DR1 Catalogue
- Date:
- 21 Oct 2024 00:54:16
- Publisher:
- ASTRON
- Description:
- This service queries the continuum catalogue based on the first data release of Apertif continuum images at a central frequency 1355 MHz, with a bandwidth of ~150 MHz and angular resolution of up to 10''. The catalogue contains 249672 radio sources, many of which have been detected for the first time at these frequencies. Source extraction methods are described in Kutkin et al. 2022. A companion VO table contains the continuum images corresponding to this catalogue (see https://vo.astron.nl/apertif_dr1/q/apertif_dr1_continuum_images/form).
Number of results to display per page
Search Results
- ID:
- ivo://astron.nl/apertif_elais/q/cone
- Title:
- Apertif Elais - Catalogue
- Short Name:
- Apertif Elais
- Date:
- 24 Feb 2025 08:45:55
- Publisher:
- ASTRON
- Description:
- Apertif is a phased-array feed system for the Westerbork SynthesisRadio Telescope (WSRT), operating at 1.4 GHz and providing forty instantaneous beams over 300 MHz of bandwidth. This data release includes the image of the ELAIS-N field observed with Apertif. The image covers 25 square degree region, has an angular resolution of 18x11 arcseconds and a median background noise of 37 μJy/beam. The corresponding source catalog, complete down to the 0.3 mJy level, includes 8526 sources. https://science.astron.nl/telescopes/wsrt-apertif/apertif-data-access/data-releases/apertif-single-fields/
- ID:
- ivo://astron.nl/apertif_lockman/q/cone
- Title:
- Apertif Lockman - Catalogue
- Short Name:
- Apertif Lockman
- Date:
- 24 Feb 2025 08:51:26
- Publisher:
- ASTRON
- Description:
- Apertif is a phased-array feed system for the Westerbork Synthesis Radio Telescope (WSRT), operating at 1.4 GHz and providing forty instantaneous beams over 300 MHz of bandwidth. This data release includes the image of the Lockman Hole field observed with Apertif. The image covers 136 square degree region, has an angular resolution of 15x13 arcseconds and a median background noise of 27 μJy/beam. The corresponding source catalog, complete down to the 0.3 mJy level, includes 55166 sources. https://science.astron.nl/telescopes/wsrt-apertif/apertif-data-access/data-releases/apertif-single-fields/
- ID:
- ivo://astron.nl/arts_dr2/q/det_cone
- Title:
- Apertif Time Domain FRB detection cone search (DR2)
- Short Name:
- Detected FRB
- Date:
- 31 Jul 2024 11:50:27
- Publisher:
- ASTRON
- Description:
- This is the final, full data release from the Apertif Radio Transient System (ARTS), a supercomputing radio-telescope instrument that performed real-time FRB detection and localisation on the Westerbork Synthesis Radio Telescope (WSRT) interferometer. It reached coherent-addition sensitivity over the entire field of the view of the primary- dish beam. The Apertif FRB survey (ALERT) detected 24 new FRBs, and interferometrically localised each of these to 0.4−10 sq. arcmin. All detections are broad band and very narrow, of order 1 ms duration, with high dispersion measures. Please note that the ARTS DR2 collection includes all data from the DR1 collection.
- ID:
- ivo://astron.nl/arts_dr1/q/det_cone
- Title:
- Apertif Time Domain FRB detection cone search (DR1)
- Short Name:
- Detected FRB
- Date:
- 31 Jul 2024 11:50:09
- Publisher:
- ASTRON
- Description:
- This is the first release of data from the Apertif Radio Transient System (ARTS), a supercomputing radio-telescope instrument that performs real-time FRB detection and localisation on the Westerbork Synthesis Radio Telescope (WSRT) interferometer. It reaches coherent-addition sensitivity over the entire field of the view of the primary- dish beam. After commissioning results verified the system performed as planned, we initiated the Apertif FRB survey (ALERT). Over the first 5 weeks we observed at design sensitivity in 2019, we detected 5 new FRBs, and interferometrically localised each of these to 0.4−10 sq. arcmin. All detections are broad band and very narrow, of order 1 ms duration, and unscattered. Dispersion measures are generally high. Please note that the ARTS DR1 collection available from this end-point is superseded by the ARTS DR2 collection. DR2 includes all data from the DR1 collection that can be queried here. The ARTS DR2 FRB detection cone search can be reached at https://vo.astron.nl/arts_dr2/q/det_cone/form.
- ID:
- ivo://astron.nl/arts_dr2/q/obs_cone
- Title:
- Apertif Time Domain FRB observation cone search (DR2)
- Short Name:
- Observed FRBs
- Date:
- 31 Jul 2024 11:50:27
- Publisher:
- ASTRON
- Description:
- This is the final, full data release from the Apertif Radio Transient System (ARTS), a supercomputing radio-telescope instrument that performed real-time FRB detection and localisation on the Westerbork Synthesis Radio Telescope (WSRT) interferometer. It reached coherent-addition sensitivity over the entire field of the view of the primary- dish beam. The Apertif FRB survey (ALERT) detected 24 new FRBs, and interferometrically localised each of these to 0.4−10 sq. arcmin. All detections are broad band and very narrow, of order 1 ms duration, with high dispersion measures. Please note that the ARTS DR2 collection includes all data from the DR1 collection.
- ID:
- ivo://astron.nl/arts_dr1/q/obs_cone
- Title:
- Apertif Time Domain FRB observation cone search (DR1)
- Short Name:
- Observed FRBs
- Date:
- 31 Jul 2024 11:50:09
- Publisher:
- ASTRON
- Description:
- This is the first release of data from the Apertif Radio Transient System (ARTS), a supercomputing radio-telescope instrument that performs real-time FRB detection and localisation on the Westerbork Synthesis Radio Telescope (WSRT) interferometer. It reaches coherent-addition sensitivity over the entire field of the view of the primary- dish beam. After commissioning results verified the system performed as planned, we initiated the Apertif FRB survey (ALERT). Over the first 5 weeks we observed at design sensitivity in 2019, we detected 5 new FRBs, and interferometrically localised each of these to 0.4−10 sq. arcmin. All detections are broad band and very narrow, of order 1 ms duration, and unscattered. Dispersion measures are generally high. Please note that the ARTS DR1 collection available from this end-point is superseded by the ARTS DR2 collection. DR2 includes all data from the DR1 collection that can be queried here. The ARTS DR2 FRB observation cone search can be reached at https://vo.astron.nl/arts_dr2/q/obs_cone/form.
- ID:
- ivo://CDS.VizieR/J/ApJ/671/333
- Title:
- Aperture photometry in NGC 5194
- Short Name:
- J/ApJ/671/333
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have studied the relationship between the star formation rate (SFR), surface density, and gas surface density in the spiral galaxy M51a (NGC 5194), using multiwavelength data obtained as part of the Spitzer Infrared Nearby Galaxies Survey (SINGS). We introduce a new SFR index based on a linear combination of Halpha emission-line and 24um continuum luminosities, which provides reliable extinction-corrected ionizing fluxes and SFR densities over a wide range of dust attenuations.
- ID:
- ivo://CDS.VizieR/J/A+A/654/A6
- Title:
- Aperture photometry of the M31 PHAT clusters
- Short Name:
- J/A+A/654/A6
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- This study is the sixth of a series that investigates degeneracy and stochasticity problems present in the determination of the age, mass, extinction, and metallicity of partially resolved or unresolved star clusters in external galaxies when using Hubble Space Telescope broadband photometry. In the fifth publication, it was noticed that inconsistencies in cluster colour indices, which arise due to projected foreground and background stars on the apertures, enhance age-metallicity-extinction degeneracies. In this work we aim to present new aperture photometry results for a sample of star clusters from the M31 Panchromatic Hubble Andromeda Treasury (PHAT) survey. We employed two methods of aperture photometry. The first method is ordinary aperture photometry to measure total cluster fluxes. The second method was introduced to avoid the brightest foreground and background stars that project onto large apertures. This method employs smaller apertures, adapted to cover a central part of clusters, and applies an aperture correction, derived for the F475W passband, to other passbands.We note that this procedure is valid only for clusters without prominent systematic gradients of colour indices beyond half-light radii. We present two catalogues of star cluster aperture photometry (produced by applying ordinary aperture photometry and adaptive aperture photometry methods) with estimated uncertainties for a sample of 1181 star clusters from the M31 PHAT survey. Compared to the M31 PHAT fundamental star cluster aperture photometry catalogue published by Johnson et al., there are changes made in the following: cluster centre coordinates, aperture sizes, and sky background estimates.
- ID:
- ivo://CDS.VizieR/J/A+A/607/A78
- Title:
- APEX and IRAM spectra of CK Vul (Nova 1670)
- Short Name:
- J/A+A/607/A78
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CK Vulpeculae (CK Vul) is an enigmatic star whose outburst was observed in 1670-72. A stellar-merger event was proposed to explain its ancient eruption. We aim to investigate the composition of the molecular gas recently discovered in the remnant of CK Vul. Deriving the chemical, elemental, and isotopic composition is crucial for identifying the nature of the object and obtaining clues on its progenitor(s). We observed millimeter and submillimeter-wave spectra of CK Vul using the IRAM 30m and APEX telescopes. Radiative-transfer modeling of the observed molecular features was performed to yield isotopic ratios for various elements. The spectra of CK Vul reveal a very rich molecular environment of low excitation (T_ex_~<12K). Atomic carbon and twenty seven different molecules, including two ions, were identified. They range from simple diatomic to complex polyatomic species of up to seven atoms large. The chemical composition of the molecular gas is indicative of carbon and nitrogen-driven chemistry but oxides are also present. Additionally, the abundance of F may be enhanced. The spectra are rich in isotopologues that are very rare in most known sources. All stable isotopes of C, N, O, Si, and S are observed and their isotopic ratios are derived. The composition of the remnant's molecular gas is most peculiar and gives rise to a very unique millimeter and submillimeter spectrum. The observation of ions and complex molecules suggests the presence of a photoionizing source but its nature (a central star or shocks) remains unknown. The elemental and isotopic composition of the gas cannot be easily reconciled with standard nucleosynthesis but processing in hot CNO cycles and partial He burning can explain most of the chemical peculiarities. The isotopic ratios of CK Vul are remarkably close to those of presolar nova grains but the link of Nova 1670 to objects responsible for these grains is unclear.
