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Start Over Subject radio astronomy Content Level Research
1891. WIYN spectroscopy in the deep SWIRE field
ID:
ivo://CDS.VizieR/J/ApJS/182/625
Title:
WIYN spectroscopy in the deep SWIRE field
Short Name:
J/ApJS/182/625
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results of spectroscopy using HYDRA on the WIYN 3.5m telescope of objects in the deep SWIRE radio field. The goal of the project was to determine spectroscopic redshifts for as many of the brighter objects in the field as possible, especially those detected in the radio and at 24um. These redshifts are primarily being used in studies of galaxy evolution and the connection of that evolution to active galactic nuclei and star formation. Redshifts measured for 365 individual objects are reported. The redshifts range from 0.03 to 2.5, mostly with z<0.9. The sources were selected to be within the WIYN HYDRA field of approximately 30' in radius from the center of the SWIRE deep field, 10:46:00, +59:01:00 (J2000). Optical sources for spectroscopic observation were selected from an r-band image of the field. A priority list of spectroscopic targets was established in the following order: 20cm detections, 24m detections, galaxies with r<20 and the balance made up of fainter galaxies in the field. We provide a table listing the galaxy positions, measured redshift and error, and note any emission lines that were visible in the spectrum. In practice, almost all the galaxies with r<19 were observed including all of the radio sources and most of the 24um sources with r<20 and a sample of radio sources which had fainter optical counterparts on the r-band image.
1892. WMAP cosmic microwave background data
ID:
ivo://CDS.VizieR/J/A+A/557/L1
Title:
WMAP cosmic microwave background data
Short Name:
J/A+A/557/L1
Date:
21 Oct 2021
Publisher:
CDS
Description:
There is currently a debate over the existence of claimed statistical anomalies in the cosmic microwave background (CMB), recently confirmed in Planck data. Recent work has focussed on methods for measuring statistical significance, on masks and on secondary anisotropies as potential causes of the anomalies. We investigate simultaneously the method for accounting for masked regions and the foreground integrated Sachs-Wolfe (ISW) signal. We search for trends in different years of WMAP CMB data with different mask treatments. We reconstruct the ISW field due to the 2 Micron All-Sky Survey (2MASS) and the NRAO VLA Sky Survey (NVSS) up to l=5, and we focus on the Axis of Evil (AoE) statistic and even/odd mirror parity, both of which search for preferred axes in the Universe. We find that removing the ISW reduces the significance of these anomalies in WMAP data, though this does not exclude the possibility of exotic physics. In the spirit of reproducible research, all reconstructed maps and codes will be made available for download at http://www.cosmostat.org/anomaliesCMB.html .
1893. WMAP five-year source catalog
ID:
ivo://CDS.VizieR/J/ApJS/180/283
Title:
WMAP five-year source catalog
Short Name:
J/ApJS/180/283
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the list of point sources found in the Wilkinson Microwave Anisotropy Probe (WMAP) five-year maps. The technique used in the first-year and three-year analyses now finds 390 point sources, and the five-year source catalog is complete for regions of the sky away from the Galactic plane to a 2Jy limit, with SNR>4.7 in all bands in the least covered parts of the sky. The noise at high frequencies is still mainly radiometer noise, but at low frequencies the cosmic microwave background (CMB) anisotropy is the largest uncertainty. A separate search of CMB-free V-W maps finds 99 sources of which all but one can be identified with known radio sources. The sources seen by WMAP are not strongly polarized. Many of the WMAP sources show significant variability from year to year, with more than a 2:1 range between the minimum and maximum fluxes.
1894. WMAP observations of Planck ESZ clusters
ID:
ivo://CDS.VizieR/J/ApJ/771/137
Title:
WMAP observations of Planck ESZ clusters
Short Name:
J/ApJ/771/137
Date:
21 Oct 2021
Publisher:
CDS
Description:
We examine the Sunyaev-Zeldovich (SZ) effect in the seven year Wilkinson Microwave Anisotropy Probe (WMAP) data by cross-correlating it with the Planck Early-release Sunyaev-Zeldovich catalog (Cat. VIII/88/esz). Our analysis proceeds in two parts. We first perform a stacking analysis in which the filtered WMAP data are averaged at the locations of the 175 Planck clusters. We then perform a regression analysis to compare the mean amplitude of the SZ signal, Y_500_, in the WMAP data to the corresponding amplitude in the Planck data. The aggregate Planck clusters are detected in the seven year WMAP data with a signal-to-noise ratio of 16.3. In the regression analysis, we find that the SZ amplitude measurements agree to better than 25%: a=1.23+/-0.18 for the fit Y_500_^wmap^=aY_500_^planck^.
1895. WMAP point sources at 61 and 94GHz
ID:
ivo://CDS.VizieR/J/MNRAS/428/3048
Title:
WMAP point sources at 61 and 94GHz
Short Name:
J/MNRAS/428/3048
Date:
21 Oct 2021
Publisher:
CDS
Description:
The detection of point sources in cosmic microwave background maps is usually based on a single-frequency approach, whereby maps at each frequency are filtered separately and the spectral information on the sources is derived combining the results at the different frequencies. In contrast, in the case of multifrequency detection methods, source detection and spectral information are tightly interconnected in order to increase the source detection efficiency. In this work we apply the matched multifiltermethod to the detection of point sources in the Wilkinson Microwave Anisotropy Probe (WMAP) 7-year data at 61 and 94GHz. This linear filtering technique takes into account the spatial and the cross-power spectrum information at the same time using the spectral behaviour of the sources without making any a priori assumption about it.
1896. WMAP 3 Year Temperature Analysis
ID:
ivo://CDS.VizieR/J/ApJS/170/288
Title:
WMAP 3 Year Temperature Analysis
Short Name:
J/ApJS/170/288
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present new full-sky temperature maps in five frequency bands from 23 to 94GHz, based on data from the first 3 years of the WMAP sky survey. The new maps are consistent with the first-year maps and are more sensitive. We employ two forms of multifrequency analysis to separate astrophysical foreground signals from the CMB, each of which improves on our first-year analyses. First, we form an improved "Internal Linear Combination" (ILC) map, based solely on WMAP data, by adding a bias-correction step and by quantifying residual uncertainties in the resulting map. Second, we fit and subtract new spatial templates that trace Galactic emission; in particular, we now use low-frequency WMAP data to trace synchrotron emission instead of the 408MHz sky survey. The WMAP point source catalog is updated to include 115 new sources whose detection is made possible by the improved sky map sensitivity. We derive the angular power spectrum of the temperature anisotropy using a hybrid approach that combines a maximum likelihood estimate at low l (large angular scales) with a quadratic cross-power estimate for l>30. The resulting multifrequency spectra are analyzed for residual point source contamination. At 94GHz the unmasked sources contribute 128+/-27^{micron}^K^2^ to l(l+1)C_l_/2{pi} at l=1000. After subtracting this contribution, our best estimate of the CMB power spectrum is derived by averaging cross-power spectra from 153 statistically independent channel pairs. A simple six-parameter {LAMBDA}CDM model continues to fit CMB data and other measures of large-scale structure remarkably well. The new polarization data produce a better measurement of the optical depth to reionization, {tau}=0.089+/-0.03. This new and tighter constraint on {tau} help break a degeneracy with the scalar spectral index, which is now found to be ns=0.960+/-0.016.
1897. WMAP 3-yr sources at 16 and 33GHz
ID:
ivo://CDS.VizieR/J/MNRAS/400/984
Title:
WMAP 3-yr sources at 16 and 33GHz
Short Name:
J/MNRAS/400/984
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present follow-up observations of 97 point sources from the Wilkinson Microwave Anisotropy Probe (WMAP) 3-yr data, contained within the New Extragalactic WMAP Point Source catalogue between -4{deg}<=DE<=60{deg}; the sources form a flux-density-limited sample complete to 1.1Jy (~5{sigma}) at 33GHz. Our observations were made at 16GHz using the Arcminute Microkelvin Imager and at 33GHz with the Very Small Array (VSA).
1898. WMAP 3-yr sources at 16 and 33GHz. II.
ID:
ivo://CDS.VizieR/J/MNRAS/400/995
Title:
WMAP 3-yr sources at 16 and 33GHz. II.
Short Name:
J/MNRAS/400/995
Date:
21 Oct 2021
Publisher:
CDS
Description:
Using the Arcminute Microkelvin Imager (AMI) at 16GHz and the Very Small Array (VSA) at 33GHz to make follow-up observations of sources in the New Extragalactic WMAP Point Source catalogue, we have investigated the flux density variability in a complete sample of 97 sources over time-scales of a few months to ~1.5yr.
1899. W43-MM1 ALMA ^12^CO(2-1) datacube
ID:
ivo://CDS.VizieR/J/A+A/636/A38
Title:
W43-MM1 ALMA ^12^CO(2-1) datacube
Short Name:
J/A+A/636/A38
Date:
21 Oct 2021
Publisher:
CDS
Description:
The accretion history of protostars remains widely mysterious even though it represents one of the best ways to understand the protostellar collapse that leads to the formation of stars. Molecular outflows, which are easier to detect than the direct accretion onto the prostellar embryo, are here used to characterize the protostellar accretion phase in W43-MM1. The W43-MM1 protocluster hosts a sufficient number of protostars to statistically investigate molecular outflows in a single, homogeneous region. We used the CO(2-1) and SiO(5-4) line datacubes, taken as part of an ALMA mosaic with a 2000 AU resolution, to search for protostellar outflows, evaluate the influence that the environment has on these outflows' characteristics and put constraints on outflow variability in W43-MM1. We discovered a rich cluster of 46 outflow lobes, driven by 27 protostars with masses of 1-100M_{sun}_. The complex environment inside which these outflow lobes develop has a definite influence on their length, limiting the validity of using outflow's dynamical timescales as a proxy of the ejection timescale in clouds with high dynamics and varying conditions. We performed a detailed study of Position-Velocity (PV) diagrams of outflows that revealed clear events of episodic ejection. The time variability of W43-MM1 outflows is a general trend and is more generally observed than in nearby, low- to intermediate-mass star-forming regions. The typical timescale found between two ejecta, ~500yr, is consistent with that found in nearby protostars. If ejection episodicity reflects variability in the accretion process, either protostellar accretion is more variable or episodicity is easier to detect in high-mass star-forming regions than in nearby clouds. The timescale found between accretion events could be resulting from instabilities, associated with bursts of inflowing gas arising from the close dynamical environment of highmass star-forming cores.
1900. W49N H2O maser outflow: distance and kinematics
ID:
ivo://CDS.VizieR/J/ApJ/393/149
Title:
W49N H2O maser outflow: distance and kinematics
Short Name:
J/ApJ/393/149
Date:
21 Oct 2021
Publisher:
CDS
Description:
Study of the motions of 105 H2O maser features clustered around a newly formed star in W49N yields the kinematics of the gas flow, the distance to the source, and the spatial scale of the Milky Way. We find that the maser outflow is bipolar, with an opening angle of ~60deg and an inclination of ~40deg to the line of sight. The expansion has a constant velocity of ~18 km/s out to a radius of 0.1pc, beyond which the outflow velocity increases to greater than 200 km/s. This increase may be due to interaction with ambient material. A rotation is also present; this rotation is nearly perpendicular to the outflow axis. The rotation may be due to ram pressure from ambient material; rotation of the ring of H II regions described by Welch et al. could produce such nonradial motion. Comparison of Doppler velocities and proper motions yields a distance of 11.4+/-1.2 kpc for the maser cluster. Combining this with a kinematic distance for W49N from Galactic rotation, we obtain a value of R0, the distance to the Galactic center, of 8.1+/-1.1 kpc.