Brief program summary and its significance: "Study of the Time Variability of the Continuum and Broad Line Emission Region of Quasars and AGNs" (Vera Jatenco-Pereira, Reuven Opher - IAG/USP) The origin of AGN variability is still unknown. One approach to this problem is to look for possible correlations between the properties of the typical variability time-scale and other properties of the AGN such as luminosity and redshift (1). The broad line region (BLR) from echo mapping in quasars is consistent with the growth of the BLR size as L^0.5 (2). Echo mapping resolves micro-arcsecond scale structure in AGNs. The nucleus heats and photoionizes the surrounding gas. Observable time delays arise due to the light travel time from the nucleus to the reprocessing site (3). The Q0957+561 A, B time series data show that the source quasar has periodic oscillations at low amplitude and at least 7 frequencies centered around 5 days, suggesting g-modes of the accretion disk. A significant level of correlated radio and optical emission suggest that a fraction of the radio emission originates in the optical emission region (4). PRINCIPLE OBJECTIVES: From the study of the time variability of the continuum and broad line emissions of quasars and AGNs we expect to understand better: a) Time evolution of the broad line region; b) Structure of the broad line region; c) Distance from the nucleus of the broad line region; and d) The accretion disk near the nucleus. We would like to obtain low resolution near infrared spectroscopy of several quasars of z = 2 - 4. Required minimum field of view (arcmin): 30" Required psf (FWHM, profile details): 0.2 - 0.4 arcsec Typical target separation if multiple targets per exposure: Signal/noise required per resolution element: 500 Typical exposure time for this S/N & lunar phase: minutes, dark Anticipated photometric dynamic range required: as high as possible What additional photometric calibrations are required? The usual If IR, is tip/tilt feasible (consider isoplanatic patch)? Yes Anticipated number of separate pointings to complete program: 10 Can this program execute in a queue? Yes, perfect for it! We need several pointings to the same object in different nights. Anticipated post-focus instrumentation requirements (filters, gratings, etc.): filters Required instruments (spectral R, filters, wavelength range): Spectrograph R = 2000 How soon might you need to revisit this target with another instrument? Study of many quasars and AGN systems. Why can't this program execute on the Blanco 4m? Need higher angular resolution for weak quasars. For bright quasars Blanco may be suitable. References (for non-mainstream applications): (1) T. Alexander, in Proc. of "Astronomical Time Series" (Tel-Aviv, Dec 30, 1996 - Jan 1, 1997). (2) S. Kaspi, in Proc. of "Astronomical Time Series" (Tel-Aviv, Dec 30, 1996 - Jan 1, 1997). (3) K. Horne, in Proc. of "Astronomical Time Series" (Tel-Aviv, Dec 30, 1996 - Jan 1, 1997). (4) R. Schild and D.J. Thomson, in Proc. of "Astronomical Time Series" (Tel-Aviv, Dec 30, 1996 - Jan 1, 1997). --------------------------------------------------------------------- Brief program summary and its significance: "Imaging of High Redshift Objects in the Near Infrared" (Vera Jatenco-Pereira, Reuven Opher - IAG/USP) Damped Lyman-alpha systems are high-column-density intergalactic clouds of hydrogen, the existence of which is inferred from absorption lines appearing in the emission spectra of distant quasars. The galaxies believed to be responsible for these absorption systems have been suggested as possible progenitors of the normal disk galaxies in the Universe. Lyman-alpha systems appear to contain a substantial fraction of the baryons known to exist in galaxies today. Optical detection of a galaxy associated with a known damped Lyman-alpha absorption system at a redshift of z= 3.150 has been reported (1). The properties of this galaxy correspond closely to those expected of a young disk galaxy in the early stages of formation, and show no evidence for an active nucleus. Ultraviolet spectra of the quasar pair Q0107-025 A and B detectd four Lyman-alpha lines common to both spectra in the redshift range 0.5 < z < 0.9. These common lines indicate that the characteristic radius of the clouds has a lower limit of 160 h^{-1} kpc (2). The study of the absorption systems of many high redshift faint quasars provide information of the evolution in time (i.e. redshift) of the Damped Lyman-alpha Systems. Deep imaging in the near infrared will allow the possibility of observing the underlying protogalaxy of the absorbing system. We wish also to image the lenses in gravitational lensing systems. PRINCIPLE OBJECTIVES: Today we have spiral and eliptical galaxies, but at high redshifts (z ~ 1 - 4) the distribution of matter does not have these forms. We wish to understand the distribution of matter at these high redshifts and its evolution in time (i.e. redshift). Required minimum field of view (arcmin): 1 arcmin Required psf (FWHM, profile details): best angular resolution possible (e.g. 0.12") Typical target separation if multiple targets per exposure: 30" Signal/noise required per resolution element: 50 Typical exposure time for this S/N & lunar phase: hours, dark Anticipated photometric dynamic range required: as high as possible What additional photometric calibrations are required? Careful flat- fielding If IR, is tip/tilt feasible (consider isoplanatic patch)? Yes Anticipated number of separate pointings to complete program: 5 Can this program execute in a queue? Yes Anticipated post-focus instrumentation requirements (filters, gratings, etc.): filters Required instruments (spectral R, filters, wavelength range): Broad band filters in J and K bands How soon might you need to revisit this target with another instrument? Study of many quasars and gravitational lensing systems. Why can't this program execute on the Blanco 4m? Need higher angular resolution. References (for non-mainstream applications): (1) S.G. Djorgouski, M.A. Pahre, J. Bechtold and R. Elston, Nature 382, 234 (1996). (2) N. Denshaw, C.B. Foltz, C.D. Impey, R.J. Weyman and S.L. Morris, Nature, 373, 223 (1995).