- ID:
- ivo://CDS.VizieR/J/ApJ/749/71
- Title:
- Star polarization in the Galactic plane
- Short Name:
- J/ApJ/749/71
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This work combines new observations of NIR starlight linear polarimetry with previously simulated observations in order to constrain dynamo models of the Galactic magnetic field. Polarimetric observations were obtained with the Mimir instrument on the Perkins Telescope in Flagstaff, AZ, along a line of constant Galactic longitude ({ell}=150{deg}) with 17 pointings of the 10'x10' field of view between -75{deg}<b<10{deg}, with more frequent pointings toward the Galactic midplane. A total of 10962 stars were photometrically measured and 1116 had usable polarizations. The observed distribution of polarization position angles with Galactic latitude and the cumulative distribution function of the measured polarizations are compared to predicted values. While the predictions lack the effects of turbulence and are therefore idealized, this comparison allows significant rejection of A0-type magnetic field models. S0 and disk-even halo-odd magnetic field geometries are also rejected by the observations, but at lower significance. New predictions of spiral-type, axisymmetric magnetic fields, when combined with these new NIR observations, constrain the Galactic magnetic field spiral pitch angle to -6{deg}+/-2{deg}.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/II/292
- Title:
- Stars with ISM Polarization Observed with HPOL
- Short Name:
- II/292
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Polarization data are given for stars whose polarizations are mostly interstellar which were observed for various programs with the University of Wisconsin spectropolarimeter (HPOL) during 1989-1994, 1995-2003 and 1995-2004
- ID:
- ivo://CDS.VizieR/II/206
- Title:
- Stellar Polarization Bibliography
- Short Name:
- II/206
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This preliminary version of Bibliographic Catalogue of Stellar Polarization (BCSP) contains data about polarization measurements of more than 1600 galactic objects published during the period 1977-1981. All the information included in the Catalogue has been taken from original papers published during this period. The main goal of the Catalogue is to present necessary bibliography to explorers studying a certain object and to give them some primary polarization data concerning with it. See the full documentation in file "bcsp.doc" (or bcsp.tex)
- ID:
- ivo://CDS.VizieR/II/226
- Title:
- Stellar polarization catalogs agglomeration
- Short Name:
- II/226
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an agglomeration of stellar polarization catalogs with results for 9286 stars. We have endeavoured to eliminate errors, provide accurate positions, sensibly weight multiple observations of the same star, and provide reasonable distances.
- ID:
- ivo://CDS.VizieR/J/ApJS/201/13
- Title:
- Submm polarization of Galactic clouds
- Short Name:
- J/ApJS/201/13
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Hertz and SCUBA polarimeters, working at 350um and 850um, respectively, have measured the polarized emission in scores of Galactic clouds. Of the clouds in each data set, 17 were mapped by both instruments with good polarization signal-to-noise ratios. We present maps of each of these 17 clouds comparing the dual-wavelength polarization amplitudes and position angles at the same spatial locations.
- ID:
- ivo://CDS.VizieR/J/MNRAS/437/3265
- Title:
- Swift J1745-26 polarized jet
- Short Name:
- J/MNRAS/437/3265
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Swift J1745-26 is an X-ray binary towards the Galactic Centre that was detected when it went into outburst in 2012 September. This source is thought to be one of a growing number of sources that display `failed outbursts', in which the self-absorbed radio jets of the transient source are never fully quenched and the thermal emission from the geometrically thin inner accretion disc never fully dominates the X-ray flux. We present multifrequency data from the Very Large Array, Australia Telescope Compact Array and Karoo Array Telescope (KAT-7) radio arrays, spanning the entire period of the outburst. Our rich data set exposes radio emission that displays a high level of large-scale variability compared to the X-ray emission and deviations from the standard radio-X-ray correlation that are indicative of an unstable jet and confirm the outburst's transition from the canonical hard state to an intermediate state. We also observe steepening of the spectral index and an increase of the linear polarization to a large fraction (~50%) of the total flux, as well as a rotation of the electric vector position angle. These are consistent with a transformation from a self-absorbed compact jet to optically thin ejecta - the first time such a discrete ejection has been observed in a failed outburst - and may imply a complex magnetic field geometry.
- ID:
- ivo://CDS.VizieR/J/A+A/448/411
- Title:
- The DRAO polarization survey
- Short Name:
- J/A+A/448/411
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The fits files contain the observed and interpolated data of a survey of linear polarization (Stokes U and Q) at 1.4GHz, obtained with the 25.6-m telescope of the Dominion Radio Astrophysical Observatory in Canada. The angular resolution is 36 arcmin. The data are corrected for ground radiation and tied to absolute determinations of zero levels. Survey observations were carried out by drift scanning the sky between -29{deg} and +90{deg} declination. The fully Nyquist- sampled drift scans were observed in steps of 0.25{deg} to about 2.5{deg} in declination. The rms noise is 12mK in Stokes U and Q.
- ID:
- ivo://CDS.VizieR/J/A+A/556/A1
- Title:
- The 2.3GHz continuum survey of the GEM project
- Short Name:
- J/A+A/556/A1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Determining the spectral and spatial characteristics of the radio continuum of our Galaxy is an experimentally challenging endeavour for improving our understanding of the astrophysics of the interstellar medium. This knowledge has also become of paramount significance for cosmology, since Galactic emission is the main source of astrophysical contamination in measurements of the Cosmic Microwave Background radiation. In this paper we present the scope of the Galactic Emission Mapping (GEM) project and its results at 2.3GHz. Its observational program was conceived and developed to reveal the large scale properties of Galactic synchrotron radiation in total intensity and polarisation through a self-consistent set of radio continuum surveys between 408MHz and 10GHz. GEM's unique observational strategy and experimental design aim at the production of foreground templates in order to address the mutual inconsistencies between existing surveys.
- ID:
- ivo://CDS.VizieR/J/ApJ/833/176
- Title:
- The magnetic field of L1544. I. NIR data
- Short Name:
- J/ApJ/833/176
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The magnetic field (B-field) of the starless dark cloud L1544 has been studied using near-infrared (NIR) background starlight polarimetry (BSP) and archival data in order to characterize the properties of the plane-of-sky B-field. NIR linear polarization measurements of over 1700 stars were obtained in the H band and 201 of these were also measured in the K band. The NIR BSP properties are correlated with reddening, as traced using the Rayleigh-Jeans color excess (H-M) method, and with thermal dust emission from the L1544 cloud and envelope seen in Herschel maps. The NIR polarization position angles change at the location of the cloud and exhibit their lowest dispersion there, offering strong evidence that NIR polarization traces the plane-of-sky B-field of L1544. In this paper, the uniformity of the plane-of-sky B-field in the envelope region of L1544 is quantitatively assessed. This allows evaluation of the approach of assuming uniform field geometry when measuring relative mass-to-flux ratios in the cloud envelope and core based on averaging of the radio Zeeman observations in the envelope, as done by Crutcher et al. (2009ApJ...692..844C). In L1544, the NIR BSP shows the envelope B-field to be significantly non-uniform and likely not suitable for averaging Zeeman properties without treating intrinsic variations. Deeper analyses of the NIR BSP and related data sets, including estimates of the B-field strength and testing how it varies with position and gas density, are the subjects of later papers in this series.
- ID:
- ivo://CDS.VizieR/J/A+AS/130/133
- Title:
- UBV polarimetry of 361 A- and F-type stars
- Short Name:
- J/A+AS/130/133
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present simultaneous UBV linear polarization measurements for 361 A- and F-type stars with accurate colour excess and distance determination. These stars are distributed in 35 Kapteyn's Selected Areas, covering the third and fourth quadrants of the galactic plane (|b|<=30{deg}). The obtained polarization and the known colour excess are compared. An analysis of the polarization distribution as a function of the stellar distance is also performed.
