Monday. Had a fun Carnaval weekend.
1211.1972
Exoplanets from the Arctic: the first wide-field survey at 80 degrees north
Law et al
Continuous darkness in winter months enhance detection efficiency of planetary transit surveys and other time domain astronomy programs. Better than 1% precision light curves of 10k stars; new high-speed astrometric and photometric data reduction pipeline; test several methods for the precision flat-fielding of images from very-wide-angle cameras, and evaluate the camera's image qualities. Scintillation limited photometric precision of 1-2% in each 10s exposure. Binning short exposures into 10-min chunks provided a photometric stability of 2-3 millimagnitudes. Capable of discovering several transiting exoplanets around bright (V<9) stars.
1211.1973
Present-day Galactic evolution: low-metallicty, warm, ionized gas inflow associated with high-velocity cloud complex A
Barger et al
HVC complex A probes physical conditions of Galactic halo. First full H-alpha intensity map of Complex A across (l,b)=(124,18) to (171,53), and deep targeted observations in H-alpha, SII, NII and OI towards regions with high H I column densities, background quasars, and stars. The H-alpha deta imply that the masses of neutral and ionized material in the cloud are similar, both being greater than 1e6 Msun. ...
1211.1997
Comments on environmental effects in the origin of angular momenta in galaxies
Panko et al
Examine the orientations of galaxies in 43 rich Abell galaxy clusters belonging to superclusters and containing at least 100 members in the considered area as a function of supercluster multiplicity. Find: orientation of galaxies in the analyzed clusters is not random and the alignment decreases with supercluster richness, although the effect is statistically significant only for azimuthal angles [?]. The dependence of galaxy alignment on cluster location inside or outside a supercluster and on supercluster multiplicity clearly shows the importance of environmental effects on the origin of galaxy angular momenta. The comparison with alignment of galaxies in a sample of rich Abell clusters not belonging to superclusters is made too.
1211.2004
Ultra high energy cosmic rays: a short review
Aloisio
As the title says. 6 pages. Propagation through astrophysical backgrounds.
1211.2023
An Arecibo survey for Zeeman splitting on OH megamaser galaxies
McBride, Heiles
Results of a comprehensive survey using Arecibo observatory for Zeeman splitting of OH lines in OH megamasers (OHMs). 77 sources, no detection of maser in 8 sources, 2 sources ambiguous. 27 sources detected at low S/N or with interference that prevented placing any useful limits on the presence of B-fields. In 26 sources, possible to place upper limits on the magnitude of B-fields, typically between 10-30 mG. For 14 sources, the Stokes V spectra exhibit features consistent with Zeeman splitting. 11/14 are new detections, and the remaining 3 are re-detections of Stokes V detections. Derive B-fields associated with maser regions with magnitudes ranging from 6.1-27.6 mG. The distribution of B-field strengths suggests the B-fields on OH masing clouds in OHMs are larger than those in Galactic OH masers. The results are consistent with B-fields playing a dynamically important role in OH masing clouds in OHMs.
1211.2036
Will nonlinear peculiar velocity and inhomogeneous reionization spoil 21cm cosmology from the epoch of reionization?
Shapiro et al
The separation scheme of cosmological from astrophysical info (in the presence of NL fluctuations and ionization, density and velocity) works reasonably well early in reioinization (<40% ionized), but not late (>80% ionized).
1211.2113
Shape evolution of massive early-type galaxies: confirmation of increased disk prevalence at z>1
Chang, van der Wel, Rix, ... Zibetti,... et al
High-res VLT imaging over 0.25 sq deg to study the evolution of massive early-type galaxies since z~1. Mass-selected samples of log(M/Msun)~10.7 suhc that 'typical' L* galaxies are included at all redshifts are drawn from pre-existing photometric z surveys. Then separate the samples into different redshift slices and classify them as late- or early-type galaxies on the basis of their specific star-formation rate. Axis-ratio measurements for the ~400 early-type galaxies in the z range 0.6<z<1.8 are accurate to 0.1 or better. The projected axis-ratio distributions are then compared with lower redshift samples. Find strong evidence for evolution of the population properties: early-type galaxies at z>1 are, on average, flatter than at z<1 and the median projected axis ratio at a fixed mass decreases with redshift. However, also find that all epoch z<~2 the very most massive early-type galaxies (M>1e11.3Msun) are the roundest, with a pronounced lack among them of galaxies that are flat in projection. Merging is a pausible mechanism that can explain both results: at all epochs merging is required for early-type galaxies to grow beyond M>1e11.3Msun, and all early types over time gradually and partially loose their disk-like characteristics.
1211.2168
Can a marginally open universe amplify magnetic fields?
Shtanov, Sahni
Large-scale B-fields generated during inflation in a spatially open universe could remain astrophysically significant at the present time since they experienced superadiabatic amplification specific to a open universe. Re-examine this assertion; show that large-scale B-fields in a realistic open universe decay in much the same manner as they would in a spatially flat universe. [duh.]
1211.2230
A census of star-forming galaxies in the z~9-10 universe based on HST+Spitzer observations over 19 CLASH clusters: three candidate z~9-10 galaxies and improved constraints on the star formation rate density at z~9.2
Bouwens, .. Zitrin, Coe, Franx, Smit, .. Moustakas, ... Benitez, ... Meneghetti, Donahue, Umetsu,... et al
Search for z~9-10 galaxies in 19 clusters in CLASH; use NIR 1.6 um to constrain position of Lyman break to z~10. Systematic search yields 3 candidates. As the title says.
1211.1972
Exoplanets from the Arctic: the first wide-field survey at 80 degrees north
Law et al
Continuous darkness in winter months enhance detection efficiency of planetary transit surveys and other time domain astronomy programs. Better than 1% precision light curves of 10k stars; new high-speed astrometric and photometric data reduction pipeline; test several methods for the precision flat-fielding of images from very-wide-angle cameras, and evaluate the camera's image qualities. Scintillation limited photometric precision of 1-2% in each 10s exposure. Binning short exposures into 10-min chunks provided a photometric stability of 2-3 millimagnitudes. Capable of discovering several transiting exoplanets around bright (V<9) stars.
1211.1973
Present-day Galactic evolution: low-metallicty, warm, ionized gas inflow associated with high-velocity cloud complex A
Barger et al
HVC complex A probes physical conditions of Galactic halo. First full H-alpha intensity map of Complex A across (l,b)=(124,18) to (171,53), and deep targeted observations in H-alpha, SII, NII and OI towards regions with high H I column densities, background quasars, and stars. The H-alpha deta imply that the masses of neutral and ionized material in the cloud are similar, both being greater than 1e6 Msun. ...
1211.1997
Comments on environmental effects in the origin of angular momenta in galaxies
Panko et al
Examine the orientations of galaxies in 43 rich Abell galaxy clusters belonging to superclusters and containing at least 100 members in the considered area as a function of supercluster multiplicity. Find: orientation of galaxies in the analyzed clusters is not random and the alignment decreases with supercluster richness, although the effect is statistically significant only for azimuthal angles [?]. The dependence of galaxy alignment on cluster location inside or outside a supercluster and on supercluster multiplicity clearly shows the importance of environmental effects on the origin of galaxy angular momenta. The comparison with alignment of galaxies in a sample of rich Abell clusters not belonging to superclusters is made too.
1211.2004
Ultra high energy cosmic rays: a short review
Aloisio
As the title says. 6 pages. Propagation through astrophysical backgrounds.
1211.2023
An Arecibo survey for Zeeman splitting on OH megamaser galaxies
McBride, Heiles
Results of a comprehensive survey using Arecibo observatory for Zeeman splitting of OH lines in OH megamasers (OHMs). 77 sources, no detection of maser in 8 sources, 2 sources ambiguous. 27 sources detected at low S/N or with interference that prevented placing any useful limits on the presence of B-fields. In 26 sources, possible to place upper limits on the magnitude of B-fields, typically between 10-30 mG. For 14 sources, the Stokes V spectra exhibit features consistent with Zeeman splitting. 11/14 are new detections, and the remaining 3 are re-detections of Stokes V detections. Derive B-fields associated with maser regions with magnitudes ranging from 6.1-27.6 mG. The distribution of B-field strengths suggests the B-fields on OH masing clouds in OHMs are larger than those in Galactic OH masers. The results are consistent with B-fields playing a dynamically important role in OH masing clouds in OHMs.
1211.2036
Will nonlinear peculiar velocity and inhomogeneous reionization spoil 21cm cosmology from the epoch of reionization?
Shapiro et al
The separation scheme of cosmological from astrophysical info (in the presence of NL fluctuations and ionization, density and velocity) works reasonably well early in reioinization (<40% ionized), but not late (>80% ionized).
1211.2113
Shape evolution of massive early-type galaxies: confirmation of increased disk prevalence at z>1
Chang, van der Wel, Rix, ... Zibetti,... et al
High-res VLT imaging over 0.25 sq deg to study the evolution of massive early-type galaxies since z~1. Mass-selected samples of log(M/Msun)~10.7 suhc that 'typical' L* galaxies are included at all redshifts are drawn from pre-existing photometric z surveys. Then separate the samples into different redshift slices and classify them as late- or early-type galaxies on the basis of their specific star-formation rate. Axis-ratio measurements for the ~400 early-type galaxies in the z range 0.6<z<1.8 are accurate to 0.1 or better. The projected axis-ratio distributions are then compared with lower redshift samples. Find strong evidence for evolution of the population properties: early-type galaxies at z>1 are, on average, flatter than at z<1 and the median projected axis ratio at a fixed mass decreases with redshift. However, also find that all epoch z<~2 the very most massive early-type galaxies (M>1e11.3Msun) are the roundest, with a pronounced lack among them of galaxies that are flat in projection. Merging is a pausible mechanism that can explain both results: at all epochs merging is required for early-type galaxies to grow beyond M>1e11.3Msun, and all early types over time gradually and partially loose their disk-like characteristics.
1211.2168
Can a marginally open universe amplify magnetic fields?
Shtanov, Sahni
Large-scale B-fields generated during inflation in a spatially open universe could remain astrophysically significant at the present time since they experienced superadiabatic amplification specific to a open universe. Re-examine this assertion; show that large-scale B-fields in a realistic open universe decay in much the same manner as they would in a spatially flat universe. [duh.]
1211.2230
A census of star-forming galaxies in the z~9-10 universe based on HST+Spitzer observations over 19 CLASH clusters: three candidate z~9-10 galaxies and improved constraints on the star formation rate density at z~9.2
Bouwens, .. Zitrin, Coe, Franx, Smit, .. Moustakas, ... Benitez, ... Meneghetti, Donahue, Umetsu,... et al
Search for z~9-10 galaxies in 19 clusters in CLASH; use NIR 1.6 um to constrain position of Lyman break to z~10. Systematic search yields 3 candidates. As the title says.
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