- ID:
- ivo://astron.nl/apertif_dr1/q/apertif_dr1_spectral_cubes
- Title:
- Apertif DR1 - HI spectral cubes
- Short Name:
- Spectral cubes
- Date:
- 21 Oct 2024 00:54:16
- Publisher:
- ASTRON
- Description:
- Apertif is a phased-array feed system for the Westerbork Synthesis Radio Telescope (WSRT), providing forty instantaneous beams over 300 MHz of bandwidth. This first data release includes observations in the first year of survey operations, from 1 July 2019 through 30 June 2020. The data release includes all raw observational data for a total of 221 observations of 160 independent target fields, covering approximately one thousand square degrees of sky. A subset of processed data products, meeting specified quality assessment criteria as outlined in Adams et al. (2022), are also released. Images and cubes are released on a per beam basis, and 3374 beams (of 7640 considered) are included in this data release. The processed data products are only available for the upper 150 MHz of the band over the range 1280–1430 MHz. The first 12.5 MHz of data are flagged due to persistent RFI resulting in a nominal bandwidth of 137.5 MHz and central frequency of 1361.25 MHz. The data products are not primary-beam corrected, however the primary-beam images are provided separately that may be used for mosaicking or for correction of individual images. This service queries the spectral line cubes from the first data release of Apertif. Four line cubes are produced over a set of different frequency ranges as follows. Cube 0: 1292.5–1337.1 MHz, Cube 1: 1333.1–1377.7 MHz, Cube 2: 1373.8–1418.4 MHz, Cube 3: 1414.5–1429.3 MHz. Cube 3 is produced at full spectral resolution of 12.2 kHz while other cubes are produced with a 3-channel averaging at 36.6 kHz resolution. The cubes have a spatial extent of 1.1 deg × 1.1 deg (661 × 661 pixels, with 6''/pixel). The median noise for all line cubes, with a spectral resolution of 36.6 kHz, is 1.6 mJy/beam, corresponding to a 3-σ H I column density sensitivity of 1.8 × 10^20 atoms cm^−2 over 20 km s^−1 (for a median angular resolution of 24″ × 15″). The corresponding dirty beam cubes are also released to allow offline cleaning of source emission.
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Search Results
- ID:
- ivo://astron.nl/apertif_dr1/q/apertif_dr1_pol_cal_visibilities
- Title:
- Apertif DR1 - Polarization calibrator raw visibilities
- Short Name:
- PolCalVis
- Date:
- 21 Oct 2024 00:54:16
- Publisher:
- ASTRON
- Description:
- Apertif is a phased-array feed system for the Westerbork Synthesis Radio Telescope (WSRT), providing forty instantaneous beams over 300 MHz of bandwidth. This first data release includes observations in the first year of survey operations, from 1 July 2019 through 30 June 2020. The data release includes all raw observational data for a total of 221 observations of 160 independent target fields, covering approximately one thousand square degrees of sky. A subset of processed data products, meeting specified quality assessment criteria as outlined in Adams et al. (2022), are also released. Images and cubes are released on a per beam basis, and 3374 beams (of 7640 considered) are included in this data release. The processed data products are only available for the upper 150 MHz of the band over the range 1280–1430 MHz. The first 12.5 MHz of data are flagged due to persistent RFI resulting in a nominal bandwidth of 137.5 MHz and central frequency of 1361.25 MHz. The data products are not primary-beam corrected, however the primary-beam images are provided separately that may be used for mosaicking or for correction of individual images. The raw visibility data are provided as separate collections for the survey fields, flux calibrator and polarization calibrator observations. The tables can be joined to identify the associated calibrators for a target observation. This service queries the raw visibilities for the polarization calibrator. These are stored on tape and are not immediately available for download. The data release documentation should be consulted for up-to-date information on how to access the data.
- ID:
- ivo://astron.nl/apertif_dr1/q/apertif_dr1_polarization_cubes
- Title:
- Apertif DR1 - Polarization cubes
- Short Name:
- Pol. cubes
- Date:
- 21 Oct 2024 00:54:16
- Publisher:
- ASTRON
- Description:
- Apertif is a phased-array feed system for the Westerbork Synthesis Radio Telescope (WSRT), providing forty instantaneous beams over 300 MHz of bandwidth. This first data release includes observations in the first year of survey operations, from 1 July 2019 through 30 June 2020. The data release includes all raw observational data for a total of 221 observations of 160 independent target fields, covering approximately one thousand square degrees of sky. A subset of processed data products, meeting specified quality assessment criteria as outlined in Adams et al. (2022), are also released. Images and cubes are released on a per beam basis, and 3374 beams (of 7640 considered) are included in this data release. The processed data products are only available for the upper 150 MHz of the band over the range 1280–1430 MHz. The first 12.5 MHz of data are flagged due to persistent RFI resulting in a nominal bandwidth of 137.5 MHz and central frequency of 1361.25 MHz. The data products are not primary-beam corrected, however the primary-beam images are provided separately that may be used for mosaicking or for correction of individual images. This service queries the polarization cubes from the first data release of Apertif. In order to prevent bandwidth depolarization and enable rotation measure synthesis studies, Stokes Q and U cubes with a frequency resolution of 6.25 MHz are produced. The cubes have a smaller spatial extent of 2.7 deg × 2.7 deg (2049 × 2049 pixels, with 4''/pixel ) than the continuum or Stokes V images but still extend well beyond the primary beam.
- 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).
- 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/A+A/659/A89
- Title:
- Aperture-corrected SN Ia host properties
- Short Name:
- J/A+A/659/A89
- Date:
- 11 Mar 2022 07:19:46
- Publisher:
- CDS
- Description:
- We use type Ia supernova (SN Ia) data obtained by the Sloan Digital Sky Survey-II Supernova Survey (SDSS-II SNS) in combination with the publicly available SDSS DR16 fiber spectroscopy of supernova (SN) host galaxies to correlate SN Ia light-curve parameters and Hubble residuals with several host galaxy properties. Fixed-aperture fiber spectroscopy suffers from aperture effects: the fraction of the galaxy covered by the fiber varies depending on its projected size on the sky, and thus measured properties are not representative of the whole galaxy. The advent of integral field spectroscopy has provided a way to correct the missing light, by studying how these galaxy parameters change with the aperture size. Here we study how the standard SN host galaxy relations change once global host galaxy parameters are corrected for aperture effects. We recover previous trends on SN Hubble residuals with host galaxy properties, but we find that discarding objects with poor fiber coverage instead of correcting for aperture loss introduces biases into the sample that affect SN host galaxy relations. The net effect of applying the commonly used g-band fraction criterion is that intrinsically faint SNe Ia in high-mass galaxies are discarded, thus artificially increasing the height of the mass step by 0.02 mag and its significance. Current and next-generation fixed-aperture fiber-spectroscopy surveys, such as DES, DESI, or TiDES in 4MOST, that aim to study SN and galaxy correlations must consider, and correct for, these effects.
- 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.
