Astrophysics Seminars

The first structures of particle dark matter form by gravitationally condensing out of the smooth mass distribution of the early universe. This formation mechanism leaves these "prompt cusps" with uniquely compact r^-1.5 density profiles and links...

Neutron stars born with magnetic fields greater than 1014 G (“magnetars”) are common in the Galaxy. Approximately 10 - 50% of the young neutron star population possesses such field strengths. These objects exhibit very slow rotation, spectacular...

Stars orbiting sufficiently close to massive black holes inevitably inspiral towards the black hole due to gravitational wave radiation. The fate of such stars is subtle and depends on an interplay between tidal heating of the star, mass transfer...

Turbulence is common in astrophysical environments and is often invoked to explain the origin of non-thermal particles in various sources. However, the mechanisms responsible for accelerating particles to high non-thermal energies remain poorly...

Observations of fluctuations in the CMB provide information about primordial inhomogeneities in the universe. However, the B-mode polarization of the inflationary gravitational wave is contaminated by the Galactic dust and synchrotron foreground...

Massive stars remain a centerpiece of astrophysical research, enriching their galactic environments throughout their dynamic lives and often-explosive ends, and leaving behind compact objects as remnants. The past decade has yielded great progress...

Pulsar timing array (PTA) experiments aim to detect nHz-frequency gravitational waves using high-precision timing of millisecond pulsars. Multiple PTA collaborations have recently reported evidence for a stochastic gravitational wave background...

The common observation that Jupiter's Galilean moons resemble a miniature Solar System has long been seen as evidence that young giant planets are surrounded by circumplanetary disks of gas and dust. Recently, one circumplanetary disk - around the...

A large fraction of exoplanetary systems contain planets that orbit very close to their host stars. With orbital periods in the range of days to weeks, tidal forces become important and lead to significant orbital and physical effects on the planets...

The search for signs of life beyond Earth is a key motivator in exoplanet research.  A suitable “biosignature gas” is one that: can accumulate in an atmosphere against atmospheric radicals and other sinks; has strong atmospheric spectral features...