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501. LOFAR observations XMM-LSS field
ID:
ivo://CDS.VizieR/J/A+A/622/A4
Title:
LOFAR observations XMM-LSS field
Short Name:
J/A+A/622/A4
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present observations of the XMM Large-Scale Structure (XMM-LSS) field observed with the LOw Frequency ARray (LOFAR) at 120-168MHz. Centred at a J2000 declination of -4.5{deg}, this is a challenging field to observe with LOFAR because of its low elevation with respect to the array. The low elevation of this field reduces the effective collecting area of the telescope, thereby reducing sensitivity. This low elevation also causes the primary beam to be elongated in the north-south direction, which can introduce side lobes in the synthesised beam in this direction. However the XMM-LSS field is a key field to study because of the wealth of ancillary information, encompassing most of the electromagnetic spectrum. The field was observed for a total of 12 hours from three four-hour LOFAR tracks using the Dutch array. The final image presented encompasses ~27deg^2^, which is the region of the observations with a >50% primary beam response. Once combined, the observations reach a central rms of 280uJy/beam at 144MHz and have an angular resolution of 7.5x8.5". We present our catalogue of detected sources and investigate how our observations compare to previous radio observations. This includes investigating the flux scale calibration of these observations compared to previous measurements, the implied spectral indices of the sources, the observed source counts and corrections to obtain the true source counts, and finally the clustering of the observed radio sources.
502. LOFAR Two-metre Sky Survey Deep Fields DR1
ID:
ivo://CDS.VizieR/J/A+A/648/A2
Title:
LOFAR Two-metre Sky Survey Deep Fields DR1
Short Name:
J/A+A/648/A2
Date:
21 Oct 2021
Publisher:
CDS
Description:
The LOFAR Two-metre Sky Survey (LoTSS) will cover the full northern sky and, additionally, aims to observe the LoTSS deep fields to a noise level of <~10uJy/beam over several tens of square degrees in areas that have the most extensive ancillary data. This paper presents the ELAIS-N1 deep field, the deepest of the LoTSS deep fields to date. With an effective observing time of 163.7 hours, it reaches a root mean square (RMS) noise level of <~20uJy/beam in the central region (and below 30uJy/beam over 10 square degrees). The resolution is 6 arcsecs and 84862 radio sources were detected in the full area (68 square degrees) with 74127 sources in the highest quality area at less than 3 degrees from the pointing centre. The observation reaches a sky density of more than 5000 sources per square degree in the central region (5 square degrees).We present the calibration procedure, which addresses the special configuration of some observations and the extended bandwidth covered (115 to 177MHz; central frequency 146.2MHz) compared to standard LoTSS. We also describe the methods used to calibrate the flux density scale using cross-matching with sources detected by other radio surveys in the literature. We find the flux density uncertainty related to the flux density scale to be 6.5 per cent. By studying the variations of the flux density measurements between different epochs, we show that relative flux density calibration is reliable out to about a 3 degree radius, but that additional flux density uncertainty is present for all sources at about the 3 per cent level; this is likely to be associated with residual calibration errors, and is shown to be more significant in datasets with poorer ionosphere conditions. We also provide intra-band spectral indices, which can be useful to detect sources with unusual spectral properties. The final uncertainty in the flux densities is estimated to be 10 per cent for ELAIS-N1.
503. LOFAR Two-metre Sky Survey Deep Fields DR1
ID:
ivo://CDS.VizieR/J/A+A/648/A3
Title:
LOFAR Two-metre Sky Survey Deep Fields DR1
Short Name:
J/A+A/648/A3
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the source associations, cross-identifications, and multi-wavelength properties of the faint radio source population detected in the deep tier of the LOFAR Two Metre Sky Survey (LoTSS): the LoTSS Deep Fields. The first LoTSS Deep Fields data release consists of deep radio imaging at 150MHz of the ELAIS-N1, Lockman Hole, and Bootes fields, down to RMS sensitives of around 20, 22, and 32uJy/beam, respectively. These fields are some of the best studied extra-galactic fields in the northern sky, with existing deep, wide-area panchromatic photometry from X-ray to infrared wavelengths, covering a total of ~26 square degrees. We first generated improved multi-wavelength catalogues in ELAIS-N1 and Lockman Hole; combined with the existing catalogue for Bootes, we present forced, matched aperture photometry for over 7.2 million sources across the three fields. We identified multi-wavelength counterparts to the radio detected sources, using a combination of the Likelihood Ratio method and visual classification, which greatly enhances the scientific potential of radio surveys and allows for the characterisation of the photometric redshifts and the physical properties of the host galaxies. The final radio-optical cross-matched catalogue consists of 81951 radio-detected sources, with counterparts identified and multi-wavelength properties presented for 79820 (>97%) sources. We also examine the properties of the host galaxies, and through stacking analysis find that the radio population with no identified counterpart is likely dominated by AGN at z~3-4. This dataset contains one of the largest samples of radio-selected star-forming galaxies and active galactic nuclei (AGN) at these depths, making it ideal for studying the history of star-formation, and the evolution of galaxies and AGN across cosmic time.
504. Longslit spectroscopy of local bulges
ID:
ivo://CDS.VizieR/J/ApJ/754/67
Title:
Longslit spectroscopy of local bulges
Short Name:
J/ApJ/754/67
Date:
21 Oct 2021
Publisher:
CDS
Description:
We use the Marcario Low Resolution Spectrograph (LRS) at the Hobby-Eberly- Telescope (HET) to study the kinematics of pseudobulges and classical bulges in the nearby universe. We present major-axis rotational velocities, velocity dispersions, and h3 and h4 moments derived from high-resolution (39km/s) spectra for 45 S0 to Sc galaxies; for 27 of the galaxies we also present minor axis data. We combine our kinematics with bulge-to-disk decompositions. We demonstrate for the first time that purely kinematic diagnostics of the bulge dichotomy agree systematically with those based on Sersic index. Low Sersic index bulges have both increased rotational support (higher v/sigma values) and on average lower central velocity dispersions. Further- more, we confirm that the same correlation also holds when visual morphologies are used to diagnose bulge type. The previously noted trend of photometrically flattened bulges to have shallower velocity dispersion profiles turns to be significant and systematic if the Sersic index is used to distinguish between pseudobulges and classical bulges. The anti-correlation between h3 and v/sigma observed in elliptical galaxies is also observed in intermediate type galaxies, irrespective of bulge type. Finally, we present evidence for formerly undetected counter rotation in the two systems NGC 3945 and NGC 4736.
505. LoTSS-DR1 Cross-Matched Source Catalogue
ID:
ivo://astron.nl/hetdex/lotss-dr1/cone
Title:
LoTSS-DR1 Cross-Matched Source Catalogue
Short Name:
LoTSS-DR1 Cone Search
Date:
04 Feb 2022 17:05:54
Publisher:
ASTRON
Description:
This service queries the catalog of radio sources from the LOFAR Two-metre Sky Survey First Data Release (LoTSS-DR1) that have been cross-matched with an optical or infrared counterpart. This data release contains images and catalogs that characterise the low-frequency radio emission in the region of the HETDEX Spring Field (right ascension 10h45m00s to15h30m00s and declination 45◦00′00′′ to 57◦00′00′′). A total of 325,694 radio sources are detected in a region covering 424 square degrees. The maps have a median sensitivity of 71 uJy/beam and a resolution of 6 arcsec. Optical counterparts for 71% of the radio sources have been identified and where possible photometric redshifts for these sources have been derived.
506. LoTSS-DR1 Image Archive
ID:
ivo://astron.nl/hetdex/lotss-dr1-img/imgs
Title:
LoTSS-DR1 Image Archive
Short Name:
LoTSS-DR1 images
Date:
12 Nov 2021 16:37:07
Publisher:
ASTRON
Description:
This service queries the catalog of images from the LOFAR Two-metre Sky Survey First Data Release (LoTSS-DR1). This data release contains images and catalogs that characterise the low-frequency radio emission in the region of the HETDEX Spring Field (right ascension 10h45m00s to15h30m00s and declination 45◦00′00′′ to 57◦00′00′′). A total of 325,694 radio sources are detected in a region covering 424 square degrees. The maps have a median sensitivity of 71 uJy/beam and a resolution of 6 arcsec. Optical counterparts for 71% of the radio sources have been identified and where possible photometric redshifts for these sources have been derived.
507. LoTSS-DR1 Image Cutout Service
ID:
ivo://astron.nl/hetdex/lotss-dr1-img/cutout
Title:
LoTSS-DR1 Image Cutout Service
Short Name:
LoTSS-DR1 Cutout
Date:
12 Nov 2021 16:37:07
Publisher:
ASTRON
Description:
This service provides cutouts from the images of the LOFAR Two-metre Sky Survey First Data Release (LoTSS-DR1). This data release contains images and catalogs that characterise the low-frequency radio emission in the region of the HETDEX Spring Field (right ascension 10h45m00s to15h30m00s and declination 45◦00′00′′ to 57◦00′00′′). A total of 325,694 radio sources are detected in a region covering 424 square degrees. The maps have a median sensitivity of 71 uJy/beam and a resolution of 6 arcsec. Optical counterparts for 71% of the radio sources have been identified and where possible photometric redshifts for these sources have been derived.
508. LoTSS-DR1 Raw Radio Catalogue Cone Search
ID:
ivo://astron.nl/hetdex/lotss-dr1-raw/cone
Title:
LoTSS-DR1 Raw Radio Catalogue Cone Search
Short Name:
LoTSS-DR1 Raw
Date:
12 Nov 2021 17:52:40
Publisher:
ASTRON
Description:
This service queries the catalog of radio sources from the LOFAR Two-metre Sky Survey First Data Release (LoTSS-DR1). This data release contains images and catalogs that characterise the low-frequency radio emission in the region of the HETDEX Spring Field (right ascension 10h45m00s to15h30m00s and declination 45◦00′00′′ to 57◦00′00′′). A total of 325,694 radio sources are detected in a region covering 424 square degrees. The maps have a median sensitivity of 71 uJy/beam and a resolution of 6 arcsec. Optical counterparts for 71% of the radio sources have been identified and where possible photometric redshifts for these sources have been derived.
509. LoTSS-PDR Image Archive
ID:
ivo://astron.nl/lofartier1/q_img/imgs
Title:
LoTSS-PDR Image Archive
Short Name:
LoTSS-PDR images
Date:
28 Apr 2021 10:35:08
Publisher:
ASTRON
Description:
This service queries the catalog of images from the LOFAR HBA Tier-1 preliminary data release (LoTSS-PDR). This data release contains images and catalogs that characterise the low-frequency radio emission in the region of the HETDEX Spring Field. In excess of 40,000 sources are detected in the images that cover an area of over 350 square degrees, have a resolution of 25 arcsec, and typical noise levels of less than 0.5 mJy/beam.
510. LoTSS-PDR Image Cutout Service
ID:
ivo://astron.nl/lofartier1/q_img/cutout
Title:
LoTSS-PDR Image Cutout Service
Short Name:
LoTSS-PDR Cutout
Date:
28 Apr 2021 10:35:08
Publisher:
ASTRON
Description:
This service provides cutouts from the images of the LOFAR HBA Tier-1 preliminary data release (LoTSS-PDR). This data release contains images and catalogs that characterise the low-frequency radio emission in the region of the HETDEX Spring Field. In excess of 40,000 sources are detected in the images that cover an area of over 350 square degrees, have a resolution of 25 arcsec, and typical noise levels of less than 0.5 mJy/beam.

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