7 papers · 1 filter
Disk Contamination in a sample of proper motion selected halo stars: A Comment on "Direct Detection of Galactic Halo Dark Matter", B.A. Oppenheimer et al., Science
David S. Graff
Based on a proper motion survey, Oppenheimer et al. claim the detection of a white dwarf component of the dark matter of the halo. I show that most of the white dwarfs in their sam…
Using the Supernova / Acceleration Probe (SNAP) to Search for Microlensing Events Towards the LMC
David S. Graff, Alex Kim
Microlensing experiments today have a tantalizing result; they have detected an excess of microlensing events beyond what is expected from known stellar populations. These events c…
Death of Stellar Baryonic Dark Matter Candidates
Katherine Freese, Brian Fields, David Graff
The nature of the dark matter in the Universe is one of the outstanding questions in astrophysics. In this talk, I address possible stellar baryonic contributions to the 50-90% of…
What are MACHOs? Interpreting LMC microlensing
David S. Graff
I discuss two hypotheses that might explain LMC microlensing: the Halo stellar remnant lensing hypothesis and the unvirialized LMC lensing hypothesis. I show that white dwarfs cann…
High Velocity Star Formation in the LMC
David S. Graff, Andrew P. Gould
Light-echo measurements show that SN1987A is 425 pc behind the LMC disk. It is continuing to move away from the disk at $18 \kms$. Thus, it has been suggested that SN1987A was ejec…
The velocity dispersion of LMC Carbon stars: possible detection of a kinematically distinct population
David S. Graff, Andrew P. Gould, Nicholas Suntzeff +2
We analyze the velocity residuals of 551 carbon stars relative to a rotating-disk model of the inner of the Large Magellanic Cloud (LMC). We find that the great…