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...

We present UBVRI photometry of 44 type-Ia supernovae (SN Ia) observed from 1997 to 2001 as part of a continuing monitoring campaign at the Fred Lawrence Whipple Observatory of the Harvard-Smithsonian Center for Astrophysics. The data set comprises 2190 observations and is the largest homogeneously observed and reduced sample of SN Ia to date, nearly doubling the number of well-observed, nearby SN Ia with published multicolor CCD light curves. The large sample of U-band photometry is a unique addition, with important connections to SN Ia observed at high redshift. The decline rate of SN Ia U-band light curves correlates well with the decline rate in other bands, as does the U −B color at maximum light. However, the U-band peak magnitudes show an increased dispersion relative to other bands even after accounting for extinction and decline rate, amounting to an additional ∼40% intrinsic scatter compared to B-band.Subject headings: supernovae: general -techniques: photometric Data and Reduction DiscoveryOur program of supernova photometry consists solely of follow-up; we search only our email, not the sky, to find new supernovae. A number of observers, both amateur and professional, are engaged in searching for supernovae. We rely on these searches, as well as prompt notification of candidates, coordinated by Dan Green and Brian Marsden of the IAU's Central Bureau for Astronomical Telegrams (CBAT), with confirmed SN reported in the IAU Circulars. In some cases the SN discoverers provide spectroscopic classification of the new objects, but generally spectroscopy is obtained by others, and reported separately in the IAU Circulars. With our spectroscopic SN follow-up program at the F. L. Whipple Observatory 1.5m telescope and FAST spectrograph (Fabricant et al. 1998), we have classified a large fraction of the new, nearby supernovae reported over the last several years and compiled a large spectroscopic database (Matheson et al. 2005, in preparation).Given a newly discovered and classified supernova, several factors help determine whether or not we include it in our monitoring program. Because of their importance, SN Ia are often given higher priority over other types, but factors such as ease of observability (southern targets and those discovered far to the west are less appealing), supernova phase (objects whose spectra indicate they are after maximum light are given lower priority), redshift (more nearby objects are favored), as well as the number of objects we are already monitoring are significant. Our final sample of well-observed SN Ia is not obtained from a single well-defined set of criteria, and selection effects in both the searches and follow-up may make this sample unsuitable for some applications (such as determining the intrinsic luminosity function of SN Ia, for example). A thorough discussion of the selection biases in the Calán/Tololo supernova search and follow-up campaign can be found in Hamuy & Pinto (1999).The discovery data for the sample of SN Ia presented here are given in Table 1. All of the ...

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The combination of the SDSS and the Chandra Multiwavelength Project (ChaMP) currently offers the largest and most homogeneously selected sample of nearby galaxies for investigating the relation between X-ray nuclear emission, nebular line-emission, black hole masses, and properties of the associated stellar populations. We provide X-ray spectral fits and valid uncertainties for all the galaxies with counts ranging from 2 to 1325 (mean 76, median 19). We present here novel constraints that both X-ray luminosity L X and X-ray spectral energy distribution bring to the galaxy evolutionary sequence H II → Seyfert/Transition Object → LINER → Passive suggested by optical data. In particular, we show that both L X and Γ, the slope of the power-law that best fits the 0.5 -8 keV spectra, are consistent with a clear decline in the accretion power along the sequence, corresponding to a softening of their spectra. This implies that, at z ≈ 0, or at low luminosity AGN levels, there is an anti-correlation between Γ and L/L edd , opposite to the trend exhibited by high z AGN (quasars). The turning point in the Γ − L/L edd LLAGN + quasars relation occurs near Γ ≈ 1.5 and L/L edd ≈ 0.01. Interestingly, this is identical to what stellar mass X-ray binaries exhibit, indicating that we have probably found the first empirical evidence for an intrinsic switch in the accretion mode, from advection-dominated flows to standard (disk/corona) accretion modes in supermassive black hole accretors, similar to what has been seen and proposed to happen in stellar mass black hole systems. The anti-correlation we find between Γ and L/L edd may instead indicate that stronger accretion correlates with greater absorption. Therefore the trend for softer spectra toward more luminous, high redshift, and strongly accreting (L/L edd 0.01) AGN/quasars could simply be the result of strong selection biases reflected in the dearth of type 2 quasar detections.

We have revisited the X-ray scaling relations of early type galaxies (ETG) by investigating, for the first time, the L X,Gas -M Total relation in a sample of 14 ETGs. In contrast to the large scatter (a factor of 10 2 -10 3 ) in the L X,Total -L B relation, we found a tight correlation between these physically motivated quantities with a rms deviation of a factor of 3 in L X,Gas = 10 38 -10 43 erg s -1 or M Total = a few x 10 10 -a few x 10 12 M • . More striking, this relation becomes even tighter with a rms deviation of a factor of 1.3 among the gas-rich galaxies (with L X,Gas > 10 40 erg s -1 ). In a simple power-law form, the new relation is (L X,Gas / 10 40 erg s -1 ) = (M Total / 3.2 x 10 11 M⊙) 3 . This relation is also consistent with the steep relation between the gas luminosity and temperature, L X,Gas ~ T Gas 4.5 , identified by Boroson, Kim & Fabbiano (2011), if the gas is virialized. Our results indicate that the total mass of an ETG is the primary factor in regulating the amount of hot gas. Among the gas-poor galaxies (with L X,Gas < a few x 10 39 erg s -1 ), the scatter in the L X,Gas -M Total (and L X,Gas -T Gas ) relation increases, suggesting that secondary factors (e.g., rotation, flattening, star formation history, cold gas, environment etc.) may become important.

We have re-examined the two X-ray scaling relations of early-type galaxies (ETGs), L X,GAS -L K and L X,GAS -T GAS , using 61 ATLAS 3D E and S0 galaxies observed with Chandra (including ROSAT results for a few X-ray bright galaxies with extended hot gas). With this sample, which doubles the number of ETGs available for study, we confirm the strong, steep correlations reported by Boroson et al (2011). Moreover, the larger sample allows us to investigate the effect of structural and dynamical properties of ETGs in these relations. Using the sub-sample of 11 'genuine' E galaxies with central surface brightness cores, slow stellar rotations and old stellar populations, we find that the scatter of the correlations is strongly reduced, yielding an extremely tight relation, of the form L X,GAS ~ T GAS 4.5±0.3 . The rms deviation is only 0.13 dex. For the gas-rich galaxies in this sample (L X, GAS > 10 40 erg s -1 ), this relation is consistent with recent simulations for velocity dispersion supported E galaxies. However, the tight L X,GAS -T GAS relation of genuine E galaxies extends down into the L X ~ 10 38 erg s -1 range, where simulations predict the gas to be in outflow/wind state, with resulting L X much lower than observed in our sample. The observed correlation may suggest the presence of small bound hot halos even in this low luminosity range. At the high luminosity end, the L X,GAS -T GAS correlation of core elliptical galaxies is similar to that found in samples of cD galaxies and groups, but shifted down toward relatively lower L X,GAS for a given T GAS . In particular cDs, central dominant galaxies sitting at the bottom of the potential well imposed by the group dark matter, have an order of magnitude higher L X,GAS than our sample core galaxies for the same L K and T GAS . We suggest that enhanced cooling in cDs, which have higher hot gas densities and lower entropies, could lower T GAS to the range observed in giant Es; this conclusion is supported by the presence of extended cold gas in several cDs. Instead, in the sub-sample of coreless ETGs -these galaxies also tend to show stellar rotation, a flattened galaxy figure and rejuvenation of the stellar population -L X,GAS and T GAS are not correlated. The L X -T GAS distribution of coreless ETGs is a scatter diagram clustered at L X, GAS < 10 40 erg s -1 , similar to that reported for the hot interstellar medium (ISM) of spiral galaxies, suggesting that both the energy input from star formation and the effect of galactic rotation and flattening may disrupt the hot ISM.

We employ the Chandra Multiwavelength Project (ChaMP) and the Sloan Digital Sky Survey (SDSS) to study the fraction of X-ray-active galaxies in the field to z = 0.7. We utilize spectroscopic redshifts from SDSS and ChaMP, as well as photometric redshifts from several SDSS catalogs, to compile a Parent sample of more than 100,000 SDSS galaxies and nearly 1600 Chandra X-ray detections. Detailed ChaMP volume completeness maps allow us to investigate the local fraction of active galactic nuclei (AGNs), defined as those objects having broadband X-ray luminosities L X (0.5-8 keV) 10 42 erg s −1 , as a function of absolute optical magnitude, X-ray luminosity, redshift, mass, and host color/morphological type. In five independent samples complete in redshift and i-band absolute magnitude, we determine the field AGN fraction to be between 0.16% ± 0.06% (for z 0.125 and −18 > M i > −20) and 3.80% ± 0.92% (for z 0.7 and M i < −23). We find excellent agreement between our ChaMP/SDSS field AGN fraction and the Chandra cluster AGN fraction, for samples restricted to similar redshift and absolute magnitude ranges: 1.19% ± 0.11% of ChaMP/SDSS field galaxies with 0.05 < z < 0.31 and absolute R-band magnitude more luminous than M R < −20 are AGNs. Our results are also broadly consistent with measures of the field AGN fraction in narrow, deep fields, though differences in the optical selection criteria, redshift coverage, and possible cosmic variance between fields introduce larger uncertainties in these comparisons.

BackgroundAcid–base imbalance has been reported to increase incidence of hypertension and diabetes. However, the association between diet-induced acid load and cardiovascular disease (CVD) risk in the general population has not been fully investigated.MethodsThis was a population-based, retrospectively registered cross-sectional study using nationally representative samples of 11,601 subjects from the Korea National Health and Nutrition Examination Survey 2008–2011. Individual CVD risk was evaluated using atherosclerotic cardiovascular disease (ASCVD) risk equations according to 2013 ACC/AHA guideline assessment in subjects aged 40–79 without prior CVD. Acid–base status was assessed with both the potential renal acid load (PRAL) and the dietary acid load (DAL) scores derived from nutrient intake.ResultsIndividuals in the highest PRAL tertile had a significant increase in 10 year ASCVD risks (9.6 vs. 8.5 %, P < 0.01) and tended to belong to the high-risk (10 year risk >10 %) group compared to those in the lowest PRAL tertile (odds ratio [OR] 1.23, 95 % confidence interval [CI] 1.22–1.35). The association between higher PRAL score and high CVD risk was stronger in the middle-aged group. Furthermore, a multiple logistic regression analysis also demonstrated this association (OR 1.20 95 % CI 1.01–1.43). Subgroup analysis stratified obesity or exercise status; individuals in unhealthy condition with lower PRAL scores had comparable ASCVD risk to people in the higher PRAL group that were in favorable physical condition. In addition, elevated PRAL scores were associated with high ASCVD risk independent of obesity, exercise, and insulin resistance, but not sarcopenia. Similar trends were observed with DAL scores.ConclusionDiet-induced acid load was associated with increased risk of CVD, independent of obesity and insulin resistance.