1805.05051
A likely super massive black hole revealed by its Einstein radius in Hubble Frontier Fields Images
Chen, Broadhurst, et al
At cosmological distances, gravitational lensing can provide a direct measurement of SMBH masses irrespective of their luminosities. When the BG lensed and FG lensing galaxies are well aligned, an inherent degeneracy with the mass profile of the lensing galaxy means that only constraints are possible on its SMBH mass. Here, directly measure the mass of a SMBH in the BCG of MACS J1149.5+2223 at z=0.5 through one of the multiply-lensed images of a BG spiral galaxy at z=1.49 projected close to the BCG. In this particular image, an intrinsically compact region in one of the spiral arms is lensed into an arc that curves towards the BCG center. Crucially, this arc has a radius of curvature of only ~0.6", betraying the presence of a local compact deflector. Its curvature is most simply reproduced by a point-like object with a mass of (8.4+4.3-1.8)e9Msun, similar to SMBH masses in local elliptical galaxies having comparable luminosities. The SMBH is noticeably offset by 4.4±0.3 kpc from the BCG light centre, plausibly the result of a kick imparted ~2.8e7 years ago during the merger of two SMBHs, placing it just beyond the stellar core. A similar curvature can be produced by replacing the offset SMBH with a compact galaxy having a mass of ~2e10 Msun within a cutoff radius of <4 kpc, and an unusually large M/L>50(M/L)_sun to make it undetectable in the deep Hubble Frontiers Fields image, at or close to the cluster redshift; such a lensing galaxy, however, perturbs other nearby lensed features of the spiral galaxy in an undesirable manner.
1805.05484
The C-Band All-Sky Survey (C-BASS)
Taylor
An experiment to image the whole sky in intensity and polarization at 5 GHz (where the synchrotron radiation is the dominant emission mechanism). The primary aim of C-BASS is to provide low-frequency all-sky maps of he Galactic emission which will enable accurate component separation analysis of both existing and future CMB intensity and polarization imaging surveys. Here, present an overview of the experiment and an update on the current status of observations. Present simulation results showing the expected improvement in the recovery of CMB and foreground signals when including C-BASS data as an additional low-frequency channel, both for intensity and polarization. Also present preliminary results from the northern part of the sky survey.
1805.05834
Using Deep Space Climate Observatory Measurements to study the Earth as an Exoplanet
Jiang, et al
Even though it was not designed as an exoplanetary research mission, the Deep Space Climate Observatory (DSCOVR) has been opportunistically used for a novel experiment, in which Earth serves as a proxy exoplanet. More than 2 years of DSCOVR Earth images were employed to produce time series of multi-wavelength, single-point light sources, in order to extract information on planetary rotation, cloud patterns, surface type, and orbit around the Sun. In what follows, assume that these properties of the Earth are unknown, and instead attempt to derive them from first principles. These conclusions are then compared with known data about our planet. Also used the DSCOVR data to simulate phase angle changes, as well as the minimum data collection rate needed to determine the rotation period of an exoplanet. This innovative method of using the time evolution of a multi-wavelength, reflected single-point light source, can be deployed for retrieving a range of intrinsic properties of an exoplanet around a distant star.
A likely super massive black hole revealed by its Einstein radius in Hubble Frontier Fields Images
Chen, Broadhurst, et al
At cosmological distances, gravitational lensing can provide a direct measurement of SMBH masses irrespective of their luminosities. When the BG lensed and FG lensing galaxies are well aligned, an inherent degeneracy with the mass profile of the lensing galaxy means that only constraints are possible on its SMBH mass. Here, directly measure the mass of a SMBH in the BCG of MACS J1149.5+2223 at z=0.5 through one of the multiply-lensed images of a BG spiral galaxy at z=1.49 projected close to the BCG. In this particular image, an intrinsically compact region in one of the spiral arms is lensed into an arc that curves towards the BCG center. Crucially, this arc has a radius of curvature of only ~0.6", betraying the presence of a local compact deflector. Its curvature is most simply reproduced by a point-like object with a mass of (8.4+4.3-1.8)e9Msun, similar to SMBH masses in local elliptical galaxies having comparable luminosities. The SMBH is noticeably offset by 4.4±0.3 kpc from the BCG light centre, plausibly the result of a kick imparted ~2.8e7 years ago during the merger of two SMBHs, placing it just beyond the stellar core. A similar curvature can be produced by replacing the offset SMBH with a compact galaxy having a mass of ~2e10 Msun within a cutoff radius of <4 kpc, and an unusually large M/L>50(M/L)_sun to make it undetectable in the deep Hubble Frontiers Fields image, at or close to the cluster redshift; such a lensing galaxy, however, perturbs other nearby lensed features of the spiral galaxy in an undesirable manner.
1805.05484
The C-Band All-Sky Survey (C-BASS)
Taylor
An experiment to image the whole sky in intensity and polarization at 5 GHz (where the synchrotron radiation is the dominant emission mechanism). The primary aim of C-BASS is to provide low-frequency all-sky maps of he Galactic emission which will enable accurate component separation analysis of both existing and future CMB intensity and polarization imaging surveys. Here, present an overview of the experiment and an update on the current status of observations. Present simulation results showing the expected improvement in the recovery of CMB and foreground signals when including C-BASS data as an additional low-frequency channel, both for intensity and polarization. Also present preliminary results from the northern part of the sky survey.
1805.05834
Using Deep Space Climate Observatory Measurements to study the Earth as an Exoplanet
Jiang, et al
Even though it was not designed as an exoplanetary research mission, the Deep Space Climate Observatory (DSCOVR) has been opportunistically used for a novel experiment, in which Earth serves as a proxy exoplanet. More than 2 years of DSCOVR Earth images were employed to produce time series of multi-wavelength, single-point light sources, in order to extract information on planetary rotation, cloud patterns, surface type, and orbit around the Sun. In what follows, assume that these properties of the Earth are unknown, and instead attempt to derive them from first principles. These conclusions are then compared with known data about our planet. Also used the DSCOVR data to simulate phase angle changes, as well as the minimum data collection rate needed to determine the rotation period of an exoplanet. This innovative method of using the time evolution of a multi-wavelength, reflected single-point light source, can be deployed for retrieving a range of intrinsic properties of an exoplanet around a distant star.
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