We have selected a sample of 30 normal (non-cD) early type galaxies, for all of which optical spectroscopy is available, and which have been observed with Chandra to a depth such to insure the detection of bright low-mass X-ray binaries (LMXBs) with L X > 10 38 erg s -1 . This sample includes a larger fraction of gas-poor galaxies than previously studied samples, and covers a wide range of stellar luminosity (L K ), velocity dispersion ( * ), GC specific frequency (S N ) and stellar age. We derive X-ray luminosities (or upper limits) from the different significant X-ray components of these galaxies: nuclei, detected and undetected LMXBs, coronally active binaries (ABs), cataclysmic variables (CVs), and hot gas. The ABs and CVs contribution is estimated from the L X -L K scaling relation of M31 and M32. The contribution of undetected LMXBs is estimated both by fitting the spectra of the unresolved X-ray emission and by extrapolating the LMXB X-ray luminosity function (XLF). On average, the X-ray luminosity of LMXBs is a factor of ~10 higher than that of ABs+CVs. By spectral fitting the emission (also considering gas emission in the regions of point sources) we estimate the contribution of the hot gas. We find our sample equally divided among galaxies with L X (gas) > L X (LMXB), L X (ABCV) ≤ L X (gas) ≤ L X (LMXB) and L X (gas) < L X (ABCV).The results for the nuclei are consistent with those discussed by Pellegrini (2010). We derive a revised scaling relation between the integrated X-ray luminosity of LMXBs in a galaxy and the L K luminosity of the host galaxy: L X (LMXB)/L K ~ 10 29 erg s -1 L K -1 with 50% 1 rms; moreover, we also obtain a tighter L X (LMXB)/L K -S N relation than previously published. We revisit the relations between hot gas content and other galaxy parameters (L K ,  * ), which in most previous work was based on the integrated total Xray luminosity of the galaxy, finding a steeper L X (gas)-L K relation with larger scatter than reported in the literature. We find a positive correlation between the luminosity and temperature of the hot ISM, significantly tighter than reported by earlier studies. This relation is particularly well defined in the subsample with  * >240 km/s, where it may be related to the analogous correlation found in cD galaxies and groups/clusters. However, the gas-poor galaxies with the shallowest potentials ( * < 200 km/s) also follow this relation, contrary to the expected anti-correlation in a simple outflow/wind scenario. Galaxies with intermediate values of  * instead tend to have the same kT, while L X (gas) spans a factor of ~20; among these galaxies, we find a moderate, positive correlation between L X (gas) and the average stellar age, possibly suggesting a transition from halo retention to outflow caused by rejuvenated star formation associated with recent mergers.Subject headings: galaxies: elliptical and lenticular -X-rays: galaxies 2003; Ciotti et al 1991;Kim & Fabbiano 2004;David et al 2006). Although David et al. (2006) investigated gas properties in gas...

The X-ray populations of Local Group galaxies have been classified in detail by Einstein, ROSAT, and ASCA, revealing a mix of binaries, supernova remnants (SNRs), and H ii regions. However, these observatories were unable to resolve X-ray sources in galaxies beyond the Local Group. With Chandra's exquisite spatial resolution, we are able to resolve sources in a sample of nearby galaxies. We show that there are highly significant differences in the X-ray colors of sources in bulge and disk systems. In particular, we find that there is a population of X-ray-soft, faint sources in disk galaxies not seen in bulges and a smaller population of hard sources also seen preferentially in disk systems. These differences can be used as a basis to classify sources as low-and high-mass X-ray binaries, SNRs, and supersoft sources. We suggest that the soft sources seen preferentially in disks are probably dominated by SNRs, although we cannot rule out the possibility that they are a new population of absorbed, faint, supersoft accretion sources associated with the young stellar population. The hard sources seen in disks but not bulges we identify as high-mass X-ray binaries. While it is impossible to classify any individual source on the basis of X-ray color alone, the observations presented here suggest that it is possible to separate sources into groups dominated by one or two source types. This classification scheme is likely to be very useful in population studies, where it is crucial to distinguish between different classes of objects.

Chandra X-Ray Observatory grating spectra of the supergiant X-ray binary 4U 1700À37 reveal emission lines from hydrogen-and helium-like S, Si, Mg, and Ne in the 4-13 Å range. The spectrum also shows fluorescent lines from S and Si and a prominent Fe K line at 1.94 Å . The lines contribute to the previously unaccounted '' soft excess '' in the flux in this range at orbital % 0:7. The X-ray source was observed during intermittent flaring, and the strengths of the lines vary with the source state. The widths of the lines (FWHM % 1000 2000 km s À1 ) can result from either Compton scattering or Doppler shifts. Power spectra of the hard X-rays show red noise, and the soft X-rays and lines show in addition quasi-periodic oscillations and a power spectral break. Helium-like triplets of Si and Mg suggest that the gas is not in a pure photoionization equilibrium. We discuss whether resonant scattering could affect the line ratios or whether a portion of the wind may be heated to temperatures T $ 10 6 K.

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We present results from spectral and temporal analyses of Suzaku and RXTE observations of the high-mass Xray binary LMC X-4. Using the full 13 years of available RXTE/all-sky monitor data, we apply the ANOVA and Lomb Normalized Periodogram methods to obtain an improved superorbital period measurement of 30.32 ± 0.04 days. The phase-averaged X-ray spectra from Suzaku observations during the high state of the superorbital period can be modeled in the 0.6-50 keV band as the combination of a power law with Γ ∼ 0.6 and a highenergy cutoff at ∼25 keV, a blackbody with kT BB ∼ 0.18 keV, and emission lines from Fe K α , O VIII, and Ne IX (X Lyα). Assuming a distance of 50 kpc, the source has luminosity L X ∼ 3 × 10 38 erg s −1 in the 2-50 keV band, and the luminosity of the soft (blackbody) component is L BB ∼ 1.5 × 10 37 erg s −1 . The energyresolved pulse profiles show single-peaked soft (0.5-1 keV) and hard (6-10 keV) pulses but a more complex pattern of medium (2-10 keV) pulses; cross-correlation of the hard with the soft pulses shows a phase shift that varies between observations. We interpret these results in terms of a picture in which a precessing disk reprocesses the hard X-rays and produces the observed soft spectral component, as has been suggested for the similar sources Her X-1 and SMC X-1.