Recent Talks

Lecture 1: Fourier theory
- Continuous and discrete Fourier Transform
- Power spectra
- Window carpentry
- FFT

Lecture 2: HTRA: Current technologies
- X-ray: RXTE to ASTROSAT, Chandra, XMM, NuSTAR
- optical/IR: EMCCDs, APDs, MCP-based systems
- UV: HST, Galex

Lecture 2: Radiation processes:
- Cyclo-synchrotron
- Curvature radiation
- Compton
- Bremstrahlung
- Electron/positron pair production and annihilation

Lecture 2: ULTRASPEC
- An introduction to EMCCDs
- Instrumentation for high-speed spectroscopy: ULTRASPEC on the ESO 3.6m and NTT
- Instrumentation for high-speed photometry II: ULTRASPEC on the TNT

Lecture 1:
- Timescales across the HR diagram
- Key (optical) properties of compact objects
- Compact binary systems & accretion variability

Lecture 1: ULTRACAM
- High time-resolution astrophysics (HTRA) - what is it and why study it?
- The detection of light - an introduction to CCDs
- Instrumentation for high-speed photometry I: ULTRACAM
- ULTRACAM: science highlights

Lecture 1: HTRA: history across all wavelengths, with emphasis on space science technology
- From optical photographic to photoelectric photometry at ground-based observatories
- First discoveries in space at X-ray wavelengths, with rockets, then satellite surveys
- Fast timing capabiities of Uhuru, OAO-C, SAS-3, HEAO-1 - all with proportional counters
- X-ray pulsars, bursters
- use of fast timing to provide spatial resolution
- Larger collecting areas of EXOSAT, Ginga revealed QPOs, and (RXTE) MSXPs
- Early detectors for HST, EUVE

Lecture 1: Introduction to compact objects:  The sources of power
- Rotation (pulsars)
- Magnetic fields (Magnetars)
- Gravitation (basics of accretion in binary system with a compact star/BH)
- mass transfer
- accretion flows (hot vs cold) and interaction with compact star
(magnetised vs unmagnetised, hard surface vs no surface)
- Jet launching
- Thermo-nuclear (Novae/X-ray bursters)

ALMA, the Atacama Large Millimeter Array, was formally dedicated on March 13, 2013. After an overview of the highlights of ALMA: Science drivers, characteristic parameters and observing modes, I will discuss some of the of the tools available to obtain images and spectra from the observations  --those you might propose and those already in the data archive. I will present a real-time demonstration of a quite generic reduction of an actual ALMA dataset obtained from the public archive, starting from the (ASDM) raw data to produce good quality, publishable images with a dynamic range that reaches ~1800 (on the strongest calibrator); although still limited by systematic effects.

Planetary nebulae (PNe) are excellent tracers to study the chemistry, kinematics, and stellar populations of galaxies.  They can be used to
constrain the properties of galactic substructures and peer into the past tidal interactions.  In this talk, I present our successful GTC observations of PNe in the Northern Spur and the Giant Stream, two
most prominent substructures of M31.  The deep spectroscopy enabled detection of the weak [O III] 4363 temperature-diagnostic line in all target PNe and as a consequence, reliable determination of elemental abundances. Our PN sample have homogeneous oxygen abundances, although
slight difference between the two substructures are marginally noticed. The study of abundances and the spatial and kinematical properties of our sample leads to the tempting conclusions: 1) their progenitors might
belong to the same stellar population, and 2) the Northern Spur and the Giant Stream may have the same origin and may be explained by the stellar orbit proposed by Merrett et al.
The dwarf satellite M32 might be responsible for the two substructures. Deep spectroscopy of PNe in M32 will help to assess this hypothesis.