Massimiliano Galeazzi

We studied the spectral signature of different components of the Diffuse X-ray Background (DXB), including Local Hot Bubble (LHB), Solar Wind Charge Exchange (SWCX), Galactic Halo, and typically unresolved point sources (galaxies and AGN), in the direction of the Chandra Deep Field South (CDFS) using the 4 Ms XMM-Newton survey and Chandra 4 Ms Source Catalog. In this paper, we present our results showing how the different components contribute to the DXB below 1 keV. In particular, we have found that ~6% of the emission at 3/4 keV (all-sky average value ~ 3$\times10^{-3}$ cm$^{-6}$pc), which is typically associated with Galactic Halo (GH) and Circum-galactic medium (CGM) is, in fact, due to emission from typically unresolved galaxies. We will discuss the effect that this has on our understanding of GH and CGM, and to our understanding of the missing CGM baryons.

We studied the spectral signature of different components of the diffuse X-ray background (DXB), including Local Hot Bubble, solar wind charge exchange, galactic halo, and typically unresolved point sources (galaxies and active galactic nuclei), in the direction of the Chandra Deep Field South using the 4 Ms XMM-Newton survey and Chandra 4 Ms Source Catalog. In this paper, we present our results showing how the different components contribute to the DXB below 1 keV. In particular, we have found that ∼6% of the emission at 3 4 keV (all-sky average value ≈3 × 10⁻³ cm⁻⁶ pc), which is typically associated with galactic halo (GH) and circumgalactic medium (CGM), is, in fact, due to emission from typically unresolved galaxies. We will discuss the effect that this has on our understanding of GH and CGM and to our understanding of the missing CGM baryons.

We report the serendipitous detection of a giant X-ray flare from the source 2XMM J043527.2–144301 during an XMM-Newton observation of the high latitude molecular cloud MBM20. The source has not been previously studied at any wavelength. The X-ray flux increases by a factor of more than 52 from quiescent state to peak of flare. A 2MASS counterpart has been identified (2MASS J04352724–1443017), and near-infrared colors reveal a spectral type of M8-M8.5 and a distance of (67 ± 13) pc, placing the source in front of MBM20. Spectral analysis and source luminosity are also consistent with this conclusion. The measured distance makes this object the most distant source (by about a factor of four) at this spectral type detected in X-rays. The X-ray flare was characterized by a peak X-ray luminosity of ~8.2 × 10²⁸ erg s^–1 and integrated X-ray energy of ~2.3 × 10³² erg. The flare emission has been characterized with a two-temperature model with temperatures of ~10 and 46 MK (0.82 and 4.0 keV) and is dominated by the higher temperature component.

The Micro-X High Resolution Microcalorimeter X-ray Imaging Rocket is sounding rocket experiment that will combine a transition-edge-sensor X-ray-microcalorimeter array with a conical imaging mirror to obtain high-spectral-resolution images of extended and point X-ray sources. Our first target is the Puppis A supernova remnant, which will be observed in January 2011. The Micro-X observation of the bright eastern knot of Puppis A will obtain a line-dominated spectrum with up to 90,000 counts collected in 300 seconds at 2 eV resolution across the 0.3-2.5 keV band. Micro-X will utilize plasma diagnostics to determine the thermodynamic and ionization state of the plasma, to search for line shifts and broadening associated with dynamical processes, and seek evidence of ejecta enhancement. We describe the progress made in developing this payload, including the detector, cryogenics, and electronics assemblies. A detailed modeling effort has been undertaken to design a rocket-bourne adiabatic demagnetization refrigerator with sufficient magnetic shielding to allow stable operation of transition edge sensors, and the associated rocket electronics have been prototyped and tested.