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Proposal Number: 09610049

Title: Ram Pressure Stripping in the Virgo Cluster - M86 Followup

PI Name: Stephen Murray

We propose Chandra ACIS-I observations of the "tail" and "head" of M86, a galaxy that is traversing the Virgo cluster with supersonic velocity. The galaxy shows a long tail for which we wish to improve the spectral data by increasing the observing time. In addition, we are searching for a leading shock, either through a surface brightness discontinuity or shocked thermal component in the spectrum. We propose a second pointing at the leading shock region (toward M87) where the ROSAT observation suggests the presence of a sharp feature.

Proposal Number: 09610400

Title: DUST DISKS AND THE EVOLUTION OF S0 GALAXIES

PI Name: Raymond White

We propose Chandra observations of three edge-on S0 galaxies with dusty disks to determine whether their survival against sputtering is due either to their having insubstantial hot atmospheres or ongoing star formation. Since dust is readily destroyed by sputtering in hot atmospheres, one expects only small amounts due to stellar mass loss over a dust sputtering lifetime (~10^7 yr). The more substantial amounts of dust seen in these S0s indicate that dust is replenished by ongoing star formation (either residual secular star formation or that associated with a recent merger) and/or resides in a less hostile sputtering environment: an insubstantial atmosphere characterized by a low X-ray (gas) to optical (stellar) luminosity ratio. Chandra observations can constrain either case.

Proposal Number: 09610464

Title: Dust-to-gas Ratio of High Redshift Galaxies

PI Name: Xinyu Dai

We propose to observe the differential X-ray absorption in three gravitational lenses with significant optical extinctions. By combining the X-ray and optical differential absorption measurements, we will accurately measure the dust-to-gas ratio of the three cosmologically distant galaxies. Combining these new measurements with earlier measurements, we will test whether the dust-to-gas ratio evolves with redshift as predicted by simulations of dust formation and evolution. Such information is to understanding galaxy and star formation and evolution in the presence of an absorbing ISM.

Proposal Number: 09610492

Title: Reading the historical chronicle of activity of the SMBH in NGC5813 using cavities and shocks in the surrounding hot gas

PI Name: William Forman

We propose a deep observation of NGC5813 whose X-ray image shows three pairs of cavities and two shock rings. Combining this observation with the existing data, we can measure the gas temperature and density jumps at the shocks to derive the shock Mach numbers and outburst energies, determine the outburst history by measuring the spatial separation of cavities and shocks, and measure the energy output history of the SMBH by combining the inventory of bubbles and shocks with their ages and models of buoyancy and shock propagation. With its multiple cavities and shocks, NGC5813's X-ray atmosphere provides a rare opportunity to chronicle the activity of its supermassive black hole.

Proposal Number: 09610499

Title: ESO 137-001 in A3627: ISM Stripping and Intracluster X-ray Binaries

PI Name: Ming Sun

Stripping the ISM from disk galaxies in clusters has important effects on both galaxies and the ICM, e.g., galaxy transformation, changes in star formation rates and metal enrichment of the ICM. The gaseous stripped tail also permits tests for important micro-physics. However, X-ray tails of late-type cluster galaxies are rare and we have never had a chance to study one in detail. We propose a 150 ks observation of a spectacular X-ray tail of a small starburst galaxy in the rich cluster A3627, for which a 40 kpc Halpha tail and 28 intergalactic HII regions have recently been found. The deep Chandra exposure is essential to: 1) reveal intracluster ULXs and study the XRB population in the tail, 2) understand stripping of the ISM in the strong ICM wind, and 3) constrain the ICM viscosity.

Proposal Number: 09610593

Title: The X-ray emission of the Lyman-alpha emitting galaxies Haro 2 and ESO338-04

PI Name: Miguel Mas-Hesse

We propose to obtain X ray images and spectra with Chandra ACIS-S of the Lyman alpha emitting starburst galaxies ESO 338-04 and Haro 2, aiming to analyze the proposed correlation between X ray luminosity and Lyalpha emission intensity in compact starbursts. This work will be performed within our current project to characterize in detail the properties of Lyman alpha emitting starburst galaxies in the Local Universe, as a first step to properly understand the Lyman alpha emission observed from high-redshift galaxies.

Proposal Number: 09620024

Title: Black Hole X-ray Novae in M31

PI Name: Stephen Murray

During A01-7 we found >16 Black Hole X-ray Novae (BHXN) in M31 using Chandra, and with HST followup have estimated orbital periods for 6 of these. Observations are underway with HST to attempt to estimate additional periods. We propose to continue this program,mboth concentrating our scarce HST resources on a single transient which exceeds the NS Eddington limit. Only uninterrupted monitoring can yield the duty cycles and long-term lightcurves of BHXN (and other variables) in M31. Our GO+GTO programs have accumulated 590ks (ACIS+HRC) near the M31 bulge, and total Chandra exposure on M31 is now 940ks. By continuing our monitoring program through AO10 we will reach ~750ks on the bulge and >1Msec total Chandra M31 exposure.

Proposal Number: 09620084

Title: X-ray Localization of the Globular Cluster G1 in M31

PI Name: Albert Kong

Localization of the X-ray emission of the globular cluster G1 in M31 will enable us to determine the origin of the X-ray radiation. From previous X-ray observations, the emission could be either due to accretion of cluster gas by the central intermediate-mass black hole, or a typical luminous low-mass X-ray binary. However, all previous X-ray observations do not allow an accurate relative astrometry. Using Chandra, we can achieve ~0.1" relative astrometry between Chandra and optical images by utilizing multiple X-ray sources with optical counterparts. The accuracy of the astrometry will allow us to determine the nature of the X-ray emission and it may provide an independent evidence for intermediate-mass black hole in G1.

Proposal Number: 09620092

Title: Are the X-Ray Binaries in S0 Galaxies Different From Those in Ellipticals?

PI Name: Craig Sarazin

Chandra images of X-ray faint ellipticals (Es) resolved them into low mass X-ray binaries (LMXBs) plus some emission from ISM. We propose Chandra observations of three X-ray faint S0 galaxies for comparison to ellipticals. We will derive the luminosity functions (LF) of LMXBs and compare to Es; LFs provide direct evidence of the history of massive star formation and a measure of the relative numbers of NS and BH binaries. We will search for variability, limiting the duty cycle of LMXBs. We will hunt for luminous X-ray flares which may be due to microblazars. We expect ~80 LMXBs in globular clusters; we will compare these with similar sources in Es, which can constrain the formation mechanism of field LMXBs. The amount, distribution, and spectrum of any ISM gas emission will be derived.

Proposal Number: 09620136

Title: Continued M31 Monitoring for Black Hole X-ray Nova

PI Name: MICHAEL GARCIA

During A01-7 we found >16 Black Hole X-ray Novae (BHXN) in M31 using Chandra, and with HST followup have estimated orbital periods for 6 of these. Observations are underway with HST to attempt to estimate additional periods. We propose to continue this program, concentrating our scarce HST resources on a single transient which exceeds the NS Eddington limit. Only uninterrupted monitoring can yield the duty cycles and long-term lightcurves of BHXN (and other variables) in M31. Our GO+GTO programs have accumulated 300ks (ACIS) near the M31 bulge, and total ACIS exposure on M31 is now 620ks. Our monitoring program alone can amass 500ks on the bulge if continued through AO12, and combined with other programs will reach >1Msec ACIS exposure on the bulge.

Proposal Number: 09620187

Title: The Remarkably Steady Nature of Luminous LMXBs in Elliptical Galaxies

PI Name: Jimmy Irwin

Multi-epoch Chandra observations of two elliptical galaxies have shown that the most luminous LMXBs are remarkably steady, with none of the 33 >8e38 ergs/s sources in both galaxies having turned off in a 3-5 yr timespan. As a group, the minimum outburst duration must be at least 50 yr such that all of the sources remained on during this time. The two most likely explanations for this behavior is they are transient long-period, wide-orbit red giant black hole LMXBs like GRS1915+105, or persistent ultracompact black hole LMXBs. We propose to reobserve NGC1399 to establish an 8-yr baseline for monitoring its luminous sources. Along with archival data of M87, this will place stringent limits on their outburst duration to distinguish between the two competing scenarios.

Proposal Number: 09620205

Title: Monitoring the brightest ULXs in the Cartwheel

PI Name: Anna Wolter

A Chandra observation detected 16 ULXs, in the starforming southern ring of the Cartwheel, one of the most outstanding and rare examples of intense star formation triggered by the propagation of density waves.Subsequent XMM-Newton data allowed us to witness a flux variation of the brightest of these (source N.10), unraveling its compact nature. We propose a deeper look to explore further the variability properties of N.10, and that of at least 9 of the brightest ULXs, in order to asses their link with the HMXB population. A total of 200 ksec, split in 2 segments, will allow us to obtain crucial details (variability pattern, and possibly spectral shape variation) to assess the physical nature of the sources. The observation will also probe into the physics of the diffuse gas.

Proposal Number: 09620250

Title: Untangling Sombrero's X-ray Emission from Coronally Active Binaries, Cataclysmic Variables, LMXBs, and Hot Gas

PI Name: Christine Jones

We propose a deep (180 ks) ACIS-I observation of the Sombrero galaxy. At a distance of 9 Mpc, this isolated, large bulge Sa galaxy, with a highly inclined disk and surprisingly little X-ray gas, offers a unique opportunity to study the diffuse emission and the point source population. Our primary goals are 1) to examine the contribution to the ISM of mass lost from stars and the energy input to drive a wind from type Ia SN and the central AGN and 2) to take a census of the bulge X-ray populations, including LMXBs, supersoft sources, and the unresolved emission from coronally active binaries (ABs) and CVs and measure their contribution to the diffuse X-ray emission. With ~160 expected globular cluster sources, we will derive the cluster luminosity function.

Proposal Number: 09620513

Title: Galaxies across the Octaves: A Chandra Legacy Survey of SINGS Galaxies

PI Name: Leigh Jenkins

We propose to complete a rich, X-ray unbiased, multiwavelength Legacy dataset for a sample of 40 nearby galaxies. These galaxies are a distance limited (d < 10 Mpc) sample from the Spitzer Infrared Nearby Galaxy Survey (SINGS) Legacy program. The sample is now 45% complete. Our observations will detect X-ray binaries as faint as 3e36-1e37 erg/s, allowing us to constrain the X-ray binary/SFR correlation over a large range of galaxy properties and build X-ray binary Luminosity Functions for galaxies across a range of star formation histories. We will produce Legacy datasets and source catalogs for the community, and run theoretical binary population synthesis models in support of this effort.

Proposal Number: 09620553

Title: Understanding the Low-Mass X-ray Binaries in the Sculptor Dwarf Spheroidal Galaxy

PI Name: Stephen Zepf

We propose to obtain two 50 ks observations of the Sculptor Dwarf Spheroidal Galaxy. In conjunction with our series of observations in 2004 totalling 126 ks, this will allow us to study any changes over a four year baseline in the low-mass X-ray binary (LMXB) population we discovered in the initial dataset (Maccarone et al. 2005) The proposed observations will leverage the discovery of LMXBs in Sculptor and use the time baseline to address key questions about how LMXBs in the field form and evolve, and the implications of their retention in the low mass dwarf galaxy. In addition, we propose to obtain optical spectroscopy to understand why many of the optical counterparts have colors and magnitudes like those of horizontal branch stars.

Proposal Number: 09620585

Title: First X-ray Observation of the Unique Starburst Galaxy NGC 7673

PI Name: Michael Loewenstein

NGC 7673 is a unique local starburst galaxy with a much higher star formation rate than either M82 or the Antennae Galaxies, and yet is virtually unobserved in X-rays. 0.1 count/sec is expected in our proposed 60 ksec Chandra observation -- mostly in the form of soft diffuse thermal emission, and a population of High Mass X-ray Binaries that will be mostly resolved into 40 ultraluminous sources. Analysis of these components contribute to our understanding of the X-ray properties of starbursts and serves as a useful analog for the compact star forming galaxies and protogalaxies that dominate the overall star formation in the universe. As such, NGC 7673 is a keystone for locally calibrating the relation between star formation rate and hard X-ray luminosity.

Proposal Number: 09620641

Title: NGC 3599: The nearest and most recently discovered tidal disruption event

PI Name: Pilar Esquej

NGC 3599 is an optically non-active galaxy that has been discovered to meet all known criteria for objects within the tidal disruption scenario. At 11.9 Mpc it is the closest known candidate and, as such, may be an important target for future high spatial-resolution observations in other wavebands. Here we propose to observe NGC 3599 with Chandra ACIS-S for 20 ks taking advantage of its excellent spatial resolution to confirm that the X-ray flare originates in the galactic nucleus and achieve a high significance point on the light curve to test whether the decay in emission still follows the theoretical t^-5/3 law.

Proposal Number: 09620645

Title: Super starbursts

PI Name: Jonathan Gelbord

It is commonly assumed that all galaxies with X-ray luminosities above $10^{42}$erg/s harbour AGN, regardless of their optical spectral classification, due to the absence of starburst galaxies in the local universe above such extreme $L_x$. By cross-correlating the 2XMMp and SDSS DR5 catalogues we have discovered several galaxies with $L_x>10^{42}$erg/s and no optical AGN evidence. We propose to use the superb spatial resolution of Chandra to observe three of these galaxies, to determine whether the XMM-detected emission is from a single, compact (few kpc) super starburst or a blend of components (less extreme starbursts, ULXs, superwinds) on few-arcsec scales. We will also use imaging spectroscopy to test whether these is any AGN contribution that is undetected at optical wavelengths.

Proposal Number: 09620817

Title: Testing binary evolution in pristine ancient dwarf galaxies

PI Name: Rosanne Di Stefano

Dwarfs are the most populous classes of galaxies in the Universe, and provide the building blocks of galaxy formation. We propose to study the X-ray source population in 4 nearby, ancient, isolated dwarfs (Draco, Ursa Min, Sextans and Carina), down to a detection limit ~ 5E33 erg/s. Chandra's spatial resolution will allow a simpler identification of their optical counterparts, separating local sources from background AGN. We will determine whether the accretors are neutron stars or white dwarfs. We will compare the results for pristine dwarfs with those for galaxies with more recent star formation. By determining the spatial and velocity distribution of neutron stars we will have a handle on the dark matter content.

Proposal Number: 09620823

Title: Galactic Bulge Latitude Survey -3

PI Name: Jonathan Grindlay

We propose to finish the final 1/3 of our Bulge Latitude Survey (BLS) covering b= -1.5 to +1.5 at l\sim 0\deg. This will increase source statistics to measure radial gradients from SgrA* and constrain the oblateness of the bulge X-ray source population. This full BLS will complement the existing Bulge-Longitude survey and the deeper pointed surveys to measure the source content and distribution in the inner bulge. Infrared and optical imaging down to the confusion limit will enable a sensitive search for counterparts despite varying extinction across the field and will extend the logN-logS analysis for the deeper Bulge Chandra fields.

Proposal Number: 09620865

Title: A deep observation of NGC4261: understanding its unique X-ray source population, gas morphology, and jet properties.

PI Name: Andreas Zezas

The nearby early-type galaxy NGC4261 reveals strikingly asymmetric distributions of X-ray sources as seen with Chandra, and globular clusters (GC) as seen in the optical band. To address the link between these populations based on their spatial correlation, luminosity function and spectral properties, and to inve- stigate the possibility that this effect is due to the galaxy's merger history, we propose a 100ksec Chandra ACIS-S3 exposure, which will detect X-ray sources down to typical LMXB luminosities (Lx~5E37 erg/s), and HST-WFPC2 observations to obtain a deep census of the GC population over the whole galaxy. These data will also allow a detailed study of its complex gaseous component, and provide information on the unique two-sided X-ray jet.

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