Summary of my research interests


I like to work on theoretical astrophysics. The problems I have worked on since I started my research activities, when I was a graduate student, are: gravitational lensing by clusters of galaxies and large-scale structure, the intergalactic medium and its ionization, extragalactic absorption lines as a probe of the intergalactic medium, formation of galaxies, accreting neutron stars, microlensing in our Galaxy and in external galaxies, high-energy cosmic rays, and the stellar dynamics in the Galactic center.

At present, most of my work is in cosmology and related to the formation of galaxies, the distribution of gas in space and the epoch of reionization of matter in the universe. The intergalactic medium was at one time in atomic form, and it must have been ionized later as the first stars and quasars were formed in the universe. I am interested in this process of ``reionization'', and the interpretation of observations of absorption spectra of distant sources caused by the intervening intergalactic medium, as well as denser gas in the process of forming galaxies. My other main interest is the nature of the dark matter and the primordial fluctuations that gave rise to the formation of galaxies and larger structures in the universe, and the observational tools we have available to study this: gravitational lensing by galaxies, clusters of galaxies and large-scale structure, microlensing of stars or quasars by any kind of compact object, the spatial distribution of galaxies, and the structure of dark matter halos studied through the dynamics of galaxies in clusters.

Here is a list of selected publications:

1. J. Miralda-Escudé 1991, ``The Correlation Function of Galaxy Ellipticities Produced by Gravitational Lensing'', Ap. J., 380, 1.
2. J. Miralda-Escudé and M. J. Rees 1994, ``Reionization and Thermal Evolution of the Intergalactic Medium'', MNRAS, 266, 343.
3. M. Rauch, J. Miralda-Escudé, W. L. W. Sargent, J. Barlow, D. H. Weinberg, L. Hernquist, N. Katz, R. Cen, and J. P. Ostriker 1997, ``The Opacity of the Lyman Alpha Forest and Implications for Omega_b and the Ionizing Background'', Ap. J., 489, 7.
4. J. Miralda-Escudé 1998, ``Reionization of the Intergalactic Medium and the Damping Wing of the Gunn-Peterson Trough'', Ap. J., 501, 15.
5. J. Miralda-Escudé, M. Haehnelt, and M. J. Rees 2000, ``Reionization of the Inhomogeneous Universe'', ApJ, 530, 1.
6. J. Miralda-Escudé and A. Gould 2000, ``A Cluster of Black Holes at the Galactic Center'', ApJ, 545, 847.
7. P. McDonald and J. Miralda-Escudé 2001, `` The Lyman-alpha Forest Flux Distribution at z ~ 5.2 and the Evolution of the Ionizing Background'', ApJL, 549, L11.
8. X. Chen and J. Miralda-Escudé 2003, ``The Spin-Kinetic Temperature Coupling and the Heating Rate due to Lyman Alpha Scattering before Reionization: Predictions for 21 cm Emission and Absorption'', submitted to ApJ (astro-ph/0303395).

I have also written a review article in Science on The Dark Age of the Universe, describing the period of time between the emission of the Cosmic Microwave Background and the formation of the first stars, the physics of how the first stars formed, and our present knowledge of the epoch of reionization. You can access the paper here for the Abstract and for the Full Text of the article.
J. Miralda-Escudé 2003, ``The Dark Age of the Universe'', Science, 300, 1904.