The Statistical Properties of Galaxies Containing ULXs

We present a statistical analysis of the properties of galaxies containing ultraluminous X-ray objects (ULXs). Our primary goal is to establish the fraction of galaxies containing a ULX as a function of ULX luminosity. Our sample is based on ROSAT HRI observations of galaxies. We find that ~ 12% of galaxies contain at least one ULX with L_X > 10^39 erg/s and ~ 1% of galaxies contain at least one ULX with L_X > 10^40 erg/s. These ULX frequencies are lower limits since ROSAT HRI observation would miss absorbed ULXs (i.e., with N_H >~ 10^21 cm^-2) and those within ~ 10" of the nucleus (due to the positional error circle of the ROSAT HRI). The Hubble type distribution of galaxies with a ULX differs significantly from the distribution of types for nearby RC3 galaxies, but does not differ significantly from the galaxy type distribution of galaxies observed by the HRI in general. We find no increase in the mean FIR luminosity or FIR / K band luminosity ratio for galaxies with a ULX relative to galaxies observed by the HRI in general, however this result is also most likely biased by the soft bandpass of the HRI and the relatively low number of high SFR galaxies observed by the HRI with enough sensitivity to detect a ULX.Comment: Accepted by Apj. 5 pages with 4 figures formatted using emulateapj. Version with just b/w figures available at http://www.pha.jhu.edu/~ptak/paper

The Bright Ages Survey. II. Evolution of Luminosity, Dust Extinction, and Star Formation from z = 0.5 to z = 2.5

The Bright Ages Survey is a K-band-selected redshift survey over six separate fields with UBVRIzJHK imaging covering a total of 75.6 arcmin(2) and reaching K = 20-20.5. Two fields have deep HST imaging, while all are centered on possible overdensities in the z similar to 2 range. Here we report photometric redshifts and spectroscopy for this sample, which has been described in Paper I. We find 18 galaxies with spectroscopic redshifts of z > 1:5. The derived rest-frame R-band luminosity functions show strong evolution out to z = 2. The luminosity function at z = 2 shows more bright galaxies than at any other epoch, even the extrapolated z = 3 luminosity function from Shapley et al. However, the R-band integrated luminosity density remains roughly constant from to z = 0:5 to z = 2. Evolved galaxies (E, S0, Sa) show a decreasing contribution to the total R-band luminosity density with redshift. The dust extinction in our K-selected sample is moderately larger [median z = 2 E(B - V) 0:30] than that found in Lyman break galaxies, although not enough to make a significant impact on the total light or star formation found at high redshift. We measure the extinction-corrected star formation rate density at z 2, finding ρ_(SFR)(z = 1.5-2.5)= 0.093 M_⊙ yr^(-1) Mpc^(-3), consistent with a relatively flat instantaneous star formation rate from z = 1-4

The magneto-optical Faraday effect in spin liquid candidates

We propose an experiment to use the magneto-optical Faraday effect to probe the dynamic Hall conductivity of spin liquid candidates. Theory predicts that an external magnetic field will generate an internal gauge field. If the source of conductivity is in spinons with a Fermi surface, a finite Faraday rotation angle is expected. We predict the angle to scale as the square of the frequency rather than display the standard cyclotron resonance pattern. Furthermore, the Faraday effect should be able to distinguish the ground state of the spin liquid, as we predict no rotation for massless Dirac spinons. We give a semiquantitative estimate for the magnitude of the effect and find that it should be experimentally feasible to detect in both $\kappa$-(ET)$_2$Cu$_2$(CN)$_3$ and, if the spinons form a Fermi surface, Herbertsmithite. We also comment on the magneto-optical Kerr effect and show that the imaginary part of the Kerr angle may be measurable.Comment: 5 pages, 1 figur

A Proposal to Measure the Quasiparticle Poisoning Time of Majorana Bound States

We propose a method of measuring the fermion parity lifetime of Majorana fermion modes due to quasiparticle poisoning. We model quasiparticle poisoning by coupling the Majorana modes to electron reservoirs, explicitly breaking parity conservation in the system. This poisoning broadens and shortens the resonance peak associated with Majorana modes. In a two lead geometry, the poisoning decreases the correlation in current noise between the two leads from the maximal value characteristic of crossed Andreev reflection. The latter measurement allows for calculation of the poisoning rate even if temperature is much higher than the resonance width.Comment: 5 pages, 5 figure

Large-Scale Outflows in Edge-on Seyfert Galaxies. III. Kiloparsec-Scale Soft X-ray Emission

We present ROSAT PSPC and HRI images of eight galaxies selected from a distance-limited sample of 22 edge-on Seyfert galaxies. Kiloparsec-scale soft X-ray nebulae extend along the galaxy minor axes in three galaxies (NGC 2992, NGC 4388 and NGC 5506). The extended X-ray emission has 0.2-2.4 keV X-ray luminosities of $0.4-3.5 \times 10^{40} erg s^{-1}$. The X-ray nebulae are roughly co-spatial with the large-scale radio emission, suggesting that both are produced by large-scale galactic outflows. Assuming pressure balance between the radio and X-ray plasmas, the X-ray filling factor is \gapprox 10^4 times larger than the radio plasma filling factor, suggesting that large-scale outflows in Seyfert galaxies are predominantly winds of thermal X-ray emitting gas. We favor an interpretation in which large-scale outflows originate as AGN-driven jets that entrain and heat gas on kpc scales as they make their way out of the galaxy. AGN- and starburst-driven winds are also possible explanations in cases where the winds are oriented along the rotation axis of the galaxy disk.Comment: 24 pages, 7 ps figures, AASTEX 4.0, accepted for ApJ April 1, 199