1212.2090
The 2MASS Tully-Fisher survey: mapping the mass in the universe
Hong et al
2MTF aims to measure TF distances for all bright inclined spirals in 2MASS redshift survey using HI widths and 2MASS photometry. More accurate width measurements and uniform sky coverage, combine observations with other radio telescopes. New z-independent distance database, will significantly improve understanding of the mass distribution in the local universe. [proceedings]
1212.2151
AGN and QSOs in the eROSITA all-sy survey -- Part I: statistical properties
Kolodzig et al
4 yr all-sky survey, entire sky scanned 8 times: Spectrum-Roentgen-Gamma orbital observatory. Analyze statistical properties of AGN and WSOs to be detected in eRASS (eROSITA all-sky survey). From planned survey strategy, parameters of galactic and extragalactic X-ray background and results of the instrument background, compute the sensitivity map of eRASS. Using the best available z-dependent AGN X-ray LF, compute various characteristics of the eRASS AGN sample, such as the luminosity and z distributions and the brightness distribution of their optical counterparts. In 4 years, will detect about 3e6 AGN on the extragalactic sky (|b|>10 deg). Median z will be z=1 with ~40% of objects in the 1<z<2 range. There will be about 1e4-5 AGN beyond z>3 and about 2k-30k AGN beyond z=4, the exact numbers depends on the poorly known behavior of the AGN XLF in the high-z and L regimes. 10% of the brightest AGN will have >38 counts, where 10% of the faintest will have <9 counts. The optical counterparts of ~95% of AGN will be brightner than I_AB=22.5. THe planned scanning strategy will allow one to search for transient events on the time scale of a half a year and a few hours with the 0.5-2.0 keV sensitivity of 2e-14 to -13 erg/s/cm^2, respectively.
1212.2166
Detection of substructure in the gravitationally lensed quasar MG0414+0534 using mid-infrared and radio VLBI observations
MacLeod, Jones, Agol, Kochanek
As the title says. Lensing flux anomaly source verified by substructure from radio data; model it to obtain mass inside Einstein radius. No interesting limit on the M/L ratio due to its proximity to the quasar image A2. With JWST observation of flux anomalies in gravitational lenses will be simple and fast, and should constrain the abundance of substructure in DM haloes.
1212.2209
Type Iax supernovae: a new class of stellar explosion
Foley ... Filippenko, ... Jha, ... et al
Prototypical member is SN 2002cx; currently has 25 members in thie class. Similar to SNe Ia spectroscopically, but have lower maximum-light velocities 2000<v<8000 km/s, typically have lower peak magnitudes, and most have hot photospheres. Relative to SNe Ia, SNe Iax have low luminosities for their light-curve shape. There is a correlation between luminosity and light-curve shape, similar to that of SNe Ia, but offset from that of SNe Ia and with a larger scatter. Despite a host-galaxy morphology distribution that is highly skewed to late-type galaxies without any SNe Iax discovered in elliptical galaxies, there are seeveral indications that the progenitor stars are white dwarfs (WDs): evidence of C/O burning in their maximum-light spectra, low ejecta masses, strong Fe lines in their late-type spectra, a lack of X-ray detections, and deep limits on massive stars and SF at the SN sites. However, two SNe Iax show strong He lines in their spectra. The progenitor system and explosion model that best fits all of the data is a binary system of a C/O WD that accretes matter from a He star and has a significant deflagration. At least some of the time, this explosion will not disrupt the WD. Estimate that in a given volume there are 31 pm 15 SNe Iax for every 100 SNe Ia, and for every 1Msun of Fe generated by SNe Ia at z=0, SNe Iax generate 0.05 pm 0.015 Msun. Being the largest class of peculiar SNe, thousands of SNe Iax will be discovered by LSST. Future detailed observations of SNe Iax should further our understanding of both their progenitor systems and explosions as well as those of SNe Ia.
1212.2211
H-ATLAS: the cosmic abundance of dust from the far-infrared background power spectrum
Thacker, Cooray, ... et al
Angular power spectrum of CFIRB anisotropies at 250, 350, and 500 um bands. Consistent with recent measurements of the CFIRB power spectrum in Herschel-SPIRE maps; confirm the existence of a clear one-halo term of galaxy clustering on arcminute angular scales with large-scale two-halo term of clustering at 30 arcminutes to angular scales of a few degrees. The PS at the largest angular scales (esp at 250 um) is contaminated by the Galactic cirrus. The angular power spectrum is modeled using a conditional luminosity function approach to describe the spatial distribution of unresolved galaxies that make up the bulk of the CFIRB. Integrating over the dusty galaxy population responsible for the BG anisotropies, find that the cosmic abundance of dust, relative to the ritical density, to be between Omega_dust=1e-6 and 8e-6 in 0<z<3. This dust abundance is consistent with estimates of the dust content in the universe using quasar reddening and magnification measurements in the SDSS.
1212.2218
Testing diagnositcs of nuclear activity and star formation in galaxies at z>1
Trump, ... Weinder, ..., Yan, Koo, ... et al
Test effectiveness of different AGN/SF diagnostics at z~1.5. MOSFIRE spectra were observed in 3 H-band multi-slit masks in the GOODS-S field, resulting in two hour exposures of 36 emission-line galaxies. Compare X-ray data with the traditional "BPT" line ratio diagnostics and the alternative mass-excitation and color-excitation diagrams, combining new MOSFIRE IR data with previous HST/WFC3 IR spectra and multiwavelength photometry. Demonstrate that a high OIII/Hb ratio is insufficient as an AGN indicator at z>1. For the four X-ray detected galaxies, the classic BPT diagnostic (OIII/Hb vs NII/Ha and SII/Ha) remains consistent with X-ray AGN/SF classification. The X-ray data also suggest that "composite" galaxies (with intermediate AGN/SF classification) host bona-fide AGNs. Nearly 2/3 of the z~1.5 emission-line galaxies have nuclear activity detected by either X-ray or the BPT diagnostic. Compared to the X-ray and BPT classifications, the mass-excitation method remains effective at z>1, but we show that the color-excitation method requires a new calibration to successfully identify AGNs at these redshifts.
Hong et al
2MTF aims to measure TF distances for all bright inclined spirals in 2MASS redshift survey using HI widths and 2MASS photometry. More accurate width measurements and uniform sky coverage, combine observations with other radio telescopes. New z-independent distance database, will significantly improve understanding of the mass distribution in the local universe. [proceedings]
1212.2151
AGN and QSOs in the eROSITA all-sy survey -- Part I: statistical properties
Kolodzig et al
4 yr all-sky survey, entire sky scanned 8 times: Spectrum-Roentgen-Gamma orbital observatory. Analyze statistical properties of AGN and WSOs to be detected in eRASS (eROSITA all-sky survey). From planned survey strategy, parameters of galactic and extragalactic X-ray background and results of the instrument background, compute the sensitivity map of eRASS. Using the best available z-dependent AGN X-ray LF, compute various characteristics of the eRASS AGN sample, such as the luminosity and z distributions and the brightness distribution of their optical counterparts. In 4 years, will detect about 3e6 AGN on the extragalactic sky (|b|>10 deg). Median z will be z=1 with ~40% of objects in the 1<z<2 range. There will be about 1e4-5 AGN beyond z>3 and about 2k-30k AGN beyond z=4, the exact numbers depends on the poorly known behavior of the AGN XLF in the high-z and L regimes. 10% of the brightest AGN will have >38 counts, where 10% of the faintest will have <9 counts. The optical counterparts of ~95% of AGN will be brightner than I_AB=22.5. THe planned scanning strategy will allow one to search for transient events on the time scale of a half a year and a few hours with the 0.5-2.0 keV sensitivity of 2e-14 to -13 erg/s/cm^2, respectively.
1212.2166
Detection of substructure in the gravitationally lensed quasar MG0414+0534 using mid-infrared and radio VLBI observations
MacLeod, Jones, Agol, Kochanek
As the title says. Lensing flux anomaly source verified by substructure from radio data; model it to obtain mass inside Einstein radius. No interesting limit on the M/L ratio due to its proximity to the quasar image A2. With JWST observation of flux anomalies in gravitational lenses will be simple and fast, and should constrain the abundance of substructure in DM haloes.
1212.2209
Type Iax supernovae: a new class of stellar explosion
Foley ... Filippenko, ... Jha, ... et al
Prototypical member is SN 2002cx; currently has 25 members in thie class. Similar to SNe Ia spectroscopically, but have lower maximum-light velocities 2000<v<8000 km/s, typically have lower peak magnitudes, and most have hot photospheres. Relative to SNe Ia, SNe Iax have low luminosities for their light-curve shape. There is a correlation between luminosity and light-curve shape, similar to that of SNe Ia, but offset from that of SNe Ia and with a larger scatter. Despite a host-galaxy morphology distribution that is highly skewed to late-type galaxies without any SNe Iax discovered in elliptical galaxies, there are seeveral indications that the progenitor stars are white dwarfs (WDs): evidence of C/O burning in their maximum-light spectra, low ejecta masses, strong Fe lines in their late-type spectra, a lack of X-ray detections, and deep limits on massive stars and SF at the SN sites. However, two SNe Iax show strong He lines in their spectra. The progenitor system and explosion model that best fits all of the data is a binary system of a C/O WD that accretes matter from a He star and has a significant deflagration. At least some of the time, this explosion will not disrupt the WD. Estimate that in a given volume there are 31 pm 15 SNe Iax for every 100 SNe Ia, and for every 1Msun of Fe generated by SNe Ia at z=0, SNe Iax generate 0.05 pm 0.015 Msun. Being the largest class of peculiar SNe, thousands of SNe Iax will be discovered by LSST. Future detailed observations of SNe Iax should further our understanding of both their progenitor systems and explosions as well as those of SNe Ia.
1212.2211
H-ATLAS: the cosmic abundance of dust from the far-infrared background power spectrum
Thacker, Cooray, ... et al
Angular power spectrum of CFIRB anisotropies at 250, 350, and 500 um bands. Consistent with recent measurements of the CFIRB power spectrum in Herschel-SPIRE maps; confirm the existence of a clear one-halo term of galaxy clustering on arcminute angular scales with large-scale two-halo term of clustering at 30 arcminutes to angular scales of a few degrees. The PS at the largest angular scales (esp at 250 um) is contaminated by the Galactic cirrus. The angular power spectrum is modeled using a conditional luminosity function approach to describe the spatial distribution of unresolved galaxies that make up the bulk of the CFIRB. Integrating over the dusty galaxy population responsible for the BG anisotropies, find that the cosmic abundance of dust, relative to the ritical density, to be between Omega_dust=1e-6 and 8e-6 in 0<z<3. This dust abundance is consistent with estimates of the dust content in the universe using quasar reddening and magnification measurements in the SDSS.
1212.2218
Testing diagnositcs of nuclear activity and star formation in galaxies at z>1
Trump, ... Weinder, ..., Yan, Koo, ... et al
Test effectiveness of different AGN/SF diagnostics at z~1.5. MOSFIRE spectra were observed in 3 H-band multi-slit masks in the GOODS-S field, resulting in two hour exposures of 36 emission-line galaxies. Compare X-ray data with the traditional "BPT" line ratio diagnostics and the alternative mass-excitation and color-excitation diagrams, combining new MOSFIRE IR data with previous HST/WFC3 IR spectra and multiwavelength photometry. Demonstrate that a high OIII/Hb ratio is insufficient as an AGN indicator at z>1. For the four X-ray detected galaxies, the classic BPT diagnostic (OIII/Hb vs NII/Ha and SII/Ha) remains consistent with X-ray AGN/SF classification. The X-ray data also suggest that "composite" galaxies (with intermediate AGN/SF classification) host bona-fide AGNs. Nearly 2/3 of the z~1.5 emission-line galaxies have nuclear activity detected by either X-ray or the BPT diagnostic. Compared to the X-ray and BPT classifications, the mass-excitation method remains effective at z>1, but we show that the color-excitation method requires a new calibration to successfully identify AGNs at these redshifts.
No comments:
Post a Comment