introductory overview murray lewis. arecibo’s primary advantage is its unmatched sensitivity...
TRANSCRIPT
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
1985
1612 MHz
RED
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 bodiessurface mapping planets & satellitesNEO 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 (CH2NH)
The 6 hyperfine multiplets of Methanimine 111-110:
Derived Tb~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 AreciboThe impact of Arecibo’s
sensitivity
• Arecibo added to the VLBA => 4.5 times better sensitivity (Day & Momjian 2005).
VLBI and AreciboThe impact of Arecibo’s
sensitivity
14 hrs with + +
=
+ + +
7 hrs 2.5 hrs
Gamma Ray Bursts (GRBs)• With the unmatched
resolution of VLBI, Taylor et al. observed the afterglow of the GRB 030329 (800Mpc, 2600 mLY).
• Measuring the size of the afterglow places constraints on the energetics and environment of GRB 030329.
GRB 030329 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 2016+SKA is a billion dollar plus international projectseveral 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 SKAprecursor 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 10-15 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?