Thursday. Still a week behind.
1308.3299
The Herschel Stripe 82 Survey (HerS): Maps and Early Catalog
Viero, ... Devlin, Dore, ... et al
Present the first set of maps and band-merged catalog from Herschel Stripe 82 survey; observations at 250, 350, and 500 um with SPIRE on Herschel. Covers 79 deg^2 along Stripe 82 to 13.0, 12.9, and 14.8 mJy beam-1 (including confusion), respectively. The band-merged catalog contains 2.7e4 sources detected at >5 sigma. HerS designed to measure correlations with external tracers of DM density field -- either point-like (i.e., galaxies selected from radio to X-ray) or extended (i.e., clusters and gravitational lensing) -- in order to measure the bias and redshift distribution of intensities of infrared-emitting dusty SF galaxies and AGN. By locating HeRS in Stripe 82, maximize the overlap with available and upcoming cosmological surveys. The maps and catalogs available online.
1308.4405
CANDELS multi-wavelength catalogs: source detection and photometry in the GOODS-South field
Guo, ... Koekemoer, Koo, ... et al
As the title says. HST/WFC3 F105W, F125W, F160W + existing public data. Catalog based on detection in F160W band. 34,930 sources; 50% completeness at 25.9, 26.6 and 28.1 AB in F160W band, for the CANDELS wide, deep, and HUDF regions, respectively.
1308.4612
Searching for millisecond pulsars: surveys, techniques and prospects
Stovall, Lorimer, Lynch
Searches for millisecond pulsars (periods < 20 ms) in the Galactic field have undergone a renaissance in the past five years. New or recently refurbished radio telescopes utilizing cooled receivers and state-of-the-art digital data acquisition systems are carrying out surveys of the entire sky at a variety of radio frequencies. Targeted searches for millisecond pulsars in point sources identified by the Fermi Gamma-ray space telescope have proved phenomenally successful, with over 50 discoveries in the past five years. The current sample of millisecond pulsars now numbers almost 200 and, for the first time in 25 years, now outnumbers their counterparts in Galactic globular clusters. While many of these searches are motivated to find pulsars which form part of pulsar timing arrays, a wide variety of interesting systems are now being found. Following a brief overview of the millisecond pulsar phenomenon, describe these searches and present some of the highlights of the new discoveries in the past decade. Conclude with predictions and prospects for ongoing and future surveys.
1308.4633
Optical proper motion measurements of the M87 jet: new results from the Hubble space telescope
Meyer, et al
Using over 13 yrs of archival imaging, reach accuracies below 0.1c in measuring the apparent velocities of individual knots in the jet. Confirm previous findings of speeds up to 4.5c in the inner 6" of the jet, and report new speeds for optical components in the outer part of the jet. Find evidence of significant motion transverse to the jet axis on the order of 0.6c in the inner jet features, and superluminal velocities parallel and transverse to the jet in the outer knot components, with an apparent ordering of velocity vectors possibly consistent with a helical jet pattern. Previous results suggested a global deceleration over the length of the jet in the form of decreasing maximum speeds of knot components from HST-1 outward, but results suggest that superluminal speeds persist out to knot C, with large differentials in very nearby features all along the jet. Find significant apparent accelerations in directions parallel and transverse to the jet axis, along with evidence for stationary features in knots D, E, and I. These results are expected to place important constraints on detailed models of kpc-scale relativistic jets.
1308.4646
Evolution in the H I gas content of galaxy groups: pre-processing and mass assembly in the current epoch
Hess, Wilcots
Assigned ALFALFA HI detections a group membership based on an existing magnitude/volume-limited SDSS DR7 group/cluster catalog. Additionally, assigned group "proximity" membership to HI detected objects whose optical counterpart falls below the limiting optical magnitude- thereby not contributing substantially to the estimate of the group stellar mass, but significantly to the total group HI mass. Find that only 25% of the HI detected galaxies reside in groups or clusters, in contrast to approximately half of all optically detected galaxies. Further, plot the relative positions of optical and HI detections in groups as a function of parent DM halo mass to reveal strong evidence that HI is being processed in galaxies as a result of the group environment: as optical membership increases, groups become increasingly deficient of HI rich galaxies at their center and the HI distribution of galaxies in the most massive groups starts to resemble the distribution observed in comparatively more extreme cluster environments. Find that the lowest HI mass objects lose their gas first as they are processed in the group environment, and it is evident that the infall of gas rich objects is important to the continuing growth of large scale structure at the present epoch, replenishing the neutral gas supply of groups. Finally, compare results to those of cosmological simulations and find that current models cannot simultaneously predict the HI selected halo occupation distribution for both low and high mass haloes.
1308.4663
S\'{e}rsic galaxy models in weak lensing shape measurement: model bias, noise bias and their interaction
Kacprzak, Bridle, Rowe, Voigt, Zuntz, Hirsch, MacCrann
In galaxy shape measurements: Model bias occurs when the true galaxy shape is not well represented by the fitted model. Noise bias occurs due to the non-linear relationship between image pixels and galaxy shape. In this paper, investigate the potential interplay between these two effects when an imperfect model is used in the presence of high noise. Present analytical expressions for this bias, which depends on the residual difference between the model and real data. They can lead to biases not accounted for in previous calibration schemes. By measuring the model bias, noise bias and their interaction, provide a complete statistical framework for measuring galaxy shapes with model fitting methods from GREAT like images. Demonstrate the noise and model interaction bias using a simple toy model, which indicates that this effect can potentially be significant Using real galaxy images from the COSMOS quantify the strength of the model bias, noise bias and their interaction. Find that the interaction term is often a similar size to the model bias term, and is smaller than the requirements of the current and shortly upcoming galaxy surveys.
1308.3299
The Herschel Stripe 82 Survey (HerS): Maps and Early Catalog
Viero, ... Devlin, Dore, ... et al
Present the first set of maps and band-merged catalog from Herschel Stripe 82 survey; observations at 250, 350, and 500 um with SPIRE on Herschel. Covers 79 deg^2 along Stripe 82 to 13.0, 12.9, and 14.8 mJy beam-1 (including confusion), respectively. The band-merged catalog contains 2.7e4 sources detected at >5 sigma. HerS designed to measure correlations with external tracers of DM density field -- either point-like (i.e., galaxies selected from radio to X-ray) or extended (i.e., clusters and gravitational lensing) -- in order to measure the bias and redshift distribution of intensities of infrared-emitting dusty SF galaxies and AGN. By locating HeRS in Stripe 82, maximize the overlap with available and upcoming cosmological surveys. The maps and catalogs available online.
1308.4405
CANDELS multi-wavelength catalogs: source detection and photometry in the GOODS-South field
Guo, ... Koekemoer, Koo, ... et al
As the title says. HST/WFC3 F105W, F125W, F160W + existing public data. Catalog based on detection in F160W band. 34,930 sources; 50% completeness at 25.9, 26.6 and 28.1 AB in F160W band, for the CANDELS wide, deep, and HUDF regions, respectively.
1308.4612
Searching for millisecond pulsars: surveys, techniques and prospects
Stovall, Lorimer, Lynch
Searches for millisecond pulsars (periods < 20 ms) in the Galactic field have undergone a renaissance in the past five years. New or recently refurbished radio telescopes utilizing cooled receivers and state-of-the-art digital data acquisition systems are carrying out surveys of the entire sky at a variety of radio frequencies. Targeted searches for millisecond pulsars in point sources identified by the Fermi Gamma-ray space telescope have proved phenomenally successful, with over 50 discoveries in the past five years. The current sample of millisecond pulsars now numbers almost 200 and, for the first time in 25 years, now outnumbers their counterparts in Galactic globular clusters. While many of these searches are motivated to find pulsars which form part of pulsar timing arrays, a wide variety of interesting systems are now being found. Following a brief overview of the millisecond pulsar phenomenon, describe these searches and present some of the highlights of the new discoveries in the past decade. Conclude with predictions and prospects for ongoing and future surveys.
1308.4633
Optical proper motion measurements of the M87 jet: new results from the Hubble space telescope
Meyer, et al
Using over 13 yrs of archival imaging, reach accuracies below 0.1c in measuring the apparent velocities of individual knots in the jet. Confirm previous findings of speeds up to 4.5c in the inner 6" of the jet, and report new speeds for optical components in the outer part of the jet. Find evidence of significant motion transverse to the jet axis on the order of 0.6c in the inner jet features, and superluminal velocities parallel and transverse to the jet in the outer knot components, with an apparent ordering of velocity vectors possibly consistent with a helical jet pattern. Previous results suggested a global deceleration over the length of the jet in the form of decreasing maximum speeds of knot components from HST-1 outward, but results suggest that superluminal speeds persist out to knot C, with large differentials in very nearby features all along the jet. Find significant apparent accelerations in directions parallel and transverse to the jet axis, along with evidence for stationary features in knots D, E, and I. These results are expected to place important constraints on detailed models of kpc-scale relativistic jets.
1308.4646
Evolution in the H I gas content of galaxy groups: pre-processing and mass assembly in the current epoch
Hess, Wilcots
Assigned ALFALFA HI detections a group membership based on an existing magnitude/volume-limited SDSS DR7 group/cluster catalog. Additionally, assigned group "proximity" membership to HI detected objects whose optical counterpart falls below the limiting optical magnitude- thereby not contributing substantially to the estimate of the group stellar mass, but significantly to the total group HI mass. Find that only 25% of the HI detected galaxies reside in groups or clusters, in contrast to approximately half of all optically detected galaxies. Further, plot the relative positions of optical and HI detections in groups as a function of parent DM halo mass to reveal strong evidence that HI is being processed in galaxies as a result of the group environment: as optical membership increases, groups become increasingly deficient of HI rich galaxies at their center and the HI distribution of galaxies in the most massive groups starts to resemble the distribution observed in comparatively more extreme cluster environments. Find that the lowest HI mass objects lose their gas first as they are processed in the group environment, and it is evident that the infall of gas rich objects is important to the continuing growth of large scale structure at the present epoch, replenishing the neutral gas supply of groups. Finally, compare results to those of cosmological simulations and find that current models cannot simultaneously predict the HI selected halo occupation distribution for both low and high mass haloes.
1308.4663
S\'{e}rsic galaxy models in weak lensing shape measurement: model bias, noise bias and their interaction
Kacprzak, Bridle, Rowe, Voigt, Zuntz, Hirsch, MacCrann
In galaxy shape measurements: Model bias occurs when the true galaxy shape is not well represented by the fitted model. Noise bias occurs due to the non-linear relationship between image pixels and galaxy shape. In this paper, investigate the potential interplay between these two effects when an imperfect model is used in the presence of high noise. Present analytical expressions for this bias, which depends on the residual difference between the model and real data. They can lead to biases not accounted for in previous calibration schemes. By measuring the model bias, noise bias and their interaction, provide a complete statistical framework for measuring galaxy shapes with model fitting methods from GREAT like images. Demonstrate the noise and model interaction bias using a simple toy model, which indicates that this effect can potentially be significant Using real galaxy images from the COSMOS quantify the strength of the model bias, noise bias and their interaction. Find that the interaction term is often a similar size to the model bias term, and is smaller than the requirements of the current and shortly upcoming galaxy surveys.
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