Introductory Overview Murray Lewis

Arecibo’s primary advantage is its unmatched sensitivity consequent on its large collecting area

we exploit this sensitivity in many contexts passive observation of nature’s signals => radio astronomy program active observation of radar echoes => radar astronomy program => atmospheric & space science pgm.

passive observations (some) pulsar surveys MSP timing single pulse studies of pulsars observation of weak masers followup on IRAS, 2MASS, etc detection of HI from galaxies at moderate z multi-wavelength studies (Galex & SDSS) ISM studies Zeeman observations (OH, HI) in our Galaxy ++

FV Boo MHz

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passive observations ctd. more recently: Zeeman observations of ULIRGS (ie Zeeman at appreciable z) molecular-line discoveries at appreciable z variation of fundamental constants tests opportunistic synergies beam-matched to GLAST => a magnetar search (nature's extreme magnetic field physics lab)

active observations observation of micro meteors 12 cm radar observ. of Solar System bodies surface mapping planets & satellites NEO detection, their shapes, binarity, etc aeronomy programs Since funding pressure comes from NSF-AST, this meeting is intended to concentrate on AST

increasing sensitivity enlarges the potential parameter space for discovery Gregorian Upgrade => ~15 dB gain for radar prg. that led to a slew of discoveries three recent covers of Science (AAAS) first demonstration of a binary asteroid {2000DP107} (4 others detected soon after at AO) YORP effect detection from 2000 PH5 this year (Yarkovsky-O'Keefe-Radzievskii-Paddack effect) increased spatial resolution for mapping

Adding sensitivity ctd. 800 MHz single-pixel bandwidth observing added this year enabled molecular line surveys of Arp 220 => many line discoveries VLBI with Arecibo adds significant sensitivity

Methanimine (CH 2 NH) The 6 hyperfine multiplets of Methanimine : Derived T b ~1000 K. It appears to be a kilo- or mega-maser, similar to the formaldehyde emission detected in this ULIRG.

Hydrogen Cyanide (HCN) HCN is an indicator of high-mass star formation. 2 =1 direct l-type transitions of HCN with higher vibration levels (J=8-14) were detected before. However, it seems that the lines discovered here with J=4, 5, 6, have not previously been detected in any other astronomical source. 4.5 GHz 6.7 GHz 9.4 GHz

VLBI and Arecibo The impact of Arecibo’s sensitivity Arecibo added to the VLBA => 4.5 times better sensitivity (Day & Momjian 2005).

VLBI and Arecibo The impact of Arecibo’s sensitivity 14 hrs with++ = hrs 2.5 hrs

Gamma Ray Bursts (GRBs) With the unmatched resolution of VLBI, Taylor et al. observed the afterglow of the GRB (800Mpc, 2600 mLY). Measuring the size of the afterglow places constraints on the energetics and environment of GRB GRB at 8.4 GHz with VLBA, Effelsberg, Arecibo, Y27, and WSRT telescopes taken 83 days after the burst.

Proper Motion of Pulsars Can help identify their birth sites, and clarify putative pulsar--SNR associations. True ages of both pulsars and their associated SNRs may also be estimated. Accurate astrometry allows some pulsars to be traced back to their birth sites in stellar clusters.

drive for greater sensitivity at m/cm => SKA BUT the time-frame for a 10% SKA is still SKA is a billion dollar plus international project several countries have invested $100M in demonstrators US has Arecibo as a 5-10% SKA demonstrator (as well as the ATA as an LNSD concept) without NSF providing new capital for mid-SKA many ALFA surveys represent SKA precursor science future HI extragalactic work at Arecibo is clearly SKA precursor science

our concentration here should be on the 5-15 year mid-term horizon beyond the current Arecibo ALFA surveys

anticipated equipment upgrades (for astronomers) UWB receivers FPGA backends (1 GHz coherent dedispersion capability!!) phased focal arrays or multi-beam feeds rfi excision improvements small VLBI reference antenna we want to hear what you need to do the science you think will be demanded from Arecibo in 5-10 yr time

anticipated equipment upgrades (for aeronomers) HF facility - $2M funding achieved conjugate point facility in Argentina - under discussion

Motivating questions for this meeting What are the scientific priorities in fundamental astrophysics, physics, cosmology, and Solar-System studies for the next years for which the Arecibo Observatory can play a unique and critical role? What instrumentation is needed in order to fulfill Arecibo's roles? What strategic planning can be done to engage broader community involvement in Arecibo science?