相关论文: Diffuse Stellar Light at 100 kpc Scales in M87

Spiral galaxies must acquire gas to maintain their observed level of star formation beyond the next few billion years (Leroy et al. 2008). A source of this material may be the gas that resides between galaxies, but our understanding of the…

We present kinematic and photometric evidence for an accretion event in the halo of the cD galaxy M87 in the last Gyr. Using velocities for ~300 planetary nebulas (PNs) in the M87 halo, we identify a chevron-like substructure in the PN…

The emission nebula M17 contains a young ~1 Myr-old open cluster; the winds from the OB stars of this cluster have blown a superbubble around the cluster. ROSAT observations of M17 detected diffuse X-ray emission peaking at the cluster and…

We study the diffuse X-ray luminosity ($L_X$) of star forming galaxies using 2-D axisymmetric hydrodynamical simulations and analytical considerations of supernovae (SNe) driven galactic outflows. We find that the mass loading of the…

Recent XMM-Newton observations of the cooling flow gas in M87 indicate sharply decreasing oxygen, iron and silicon abundances within $\sim 5$ kpc of the galactic center. This result is unexpected since stellar mass loss and Type Ia…

When surrounded by a transparent emission region, black holes are expected to reveal a dark shadow caused by gravitational light bending and photon capture at the event horizon. To image and study this phenomenon, we have assembled the…

Fluorescent Dark Matter has been suggested as a possible explanation of both the 3.5 keV excess in the diffuse emission of the Perseus Cluster and of the deficit at the same energy in the central active galaxy within that cluster, NGC 1275.…

M17 is one of the youngest and most massive nearby star-formation regions in the Galaxy. It features a bright H II region erupting as a blister from the side of a giant molecular cloud (GMC). Combining photometry from the Spitzer GLIMPSE…

We make predictions for diffuse stellar mass fractions in dark matter halos from the scales of small spiral galaxies to those of large galaxy clusters. We use an extensively-tested analytic model for subhalo infall and evolution and…

Recent observations with the Chandra X-ray Observatory have provided us with the capability to discriminate point sources, such as the supermassive black hole Sgr A*, from the diffuse emission within the inner 10'' of the Galaxy. The hot…

The 6 billion solar mass supermassive black hole at the center of the giant elliptical galaxy M87 powers a relativistic jet. Observations at millimeter wavelengths with the Event Horizon Telescope have localized the emission from the base…

A number of theories, spanning a wide range of mass scales, predict dark matter candidates that have lifetimes much longer than the age of the universe, yet may produce a significant flux of gamma rays in their decays today. We constrain…

The arrival times, positions, and fluxes of multiple images in strong lens systems can be used to infer the presence of dark subhalos in the deflector, and thus test predictions of cold dark matter models. However, gravitational lensing…

This is the second of three papers that search for the predicted stellar cusp around the Milky Way's central black hole, Sagittarius A*, with new data and methods. We aim to infer the distribution of the faintest stellar population…

Deep Chandra exposures reveal the presence of diffuse X-ray emission with a luminosity of 1.3x10^{39} ergs s^{-1} from the spiral galaxy NGC 3184. This appears to be truly diffuse thermal emission distinct from the low-luminosity LMXB…

We present deep optical imaging of the inner 1.5 x 1.5 degrees of the Virgo cluster to search for diffuse intracluster light (ICL). Our image reaches a 1 sigma depth of mu_v=28.5 mag/arcsec^2 -- 1.5 mag/arcsec^2 deeper than previous surveys…

Theories of galaxy formation predict the existence of extended gas halo around spiral galaxies. If there are 10-100 nG magnetic fields at several ten kpc distances from the galaxies, extended galactic cosmic ray (CR) haloes could also…

We have observed twenty two galaxies at 100 microns with the Kuiper Airborne Observatory in order to determine the size of their FIR emitting regions. Most of these galaxies are luminous far-infrared sources, with L_FIR > 10^11 L_sun. This…

In this paper we revisit the Dysonian approach and assume that a superadvanced civilisation is capable of building a cosmic megastructure located closer than the habitable zone (HZ). Then such a Dyson Sphere (DS) might be visible in the…

Here is reviewed our current understanding of Galactic and extragalactic diffuse gamma-ray emission. The spectrum of the extragalactic gamma-ray background above 30 MeV can be well described by a power law with photon index s=2.1. In the…