research talk for ursi
DESCRIPTION
Presented for the Radio Astronomy and the Ionosphere session at the National Radio Sciences, Meeting in Boulder, CO, January 2010TRANSCRIPT
Probing the Ionosphere with
PAPER
Nicole Gugliucci
PAPER is a UVa/Berkeley/NRAO/UPenn/SKA-SA
Production
Outline
• How does the ionosphere affect PAPER?
• What we know from the VLA
• PAPER-16 and PAPER-32 results
• Ongoing and future work
Though Ham radio
aficionados love the
ionosphere, it is a nuisance
to low frequency radio
astronomy
http://radiojove.gsfc.nasa.gov
Fro
m K
itch
in, A
stro
ph
ysic
al
Tech
niq
ues
Precision Array to Probe the Epoch of Reionization
Precision Array to Probe the Epoch of Reionization
Courtesy of Carnarvon Circus
AIPY (and CASA)
Precision Array to Probe the Epoch of Reionization
Courtesy of Carnarvon Circus
AIPY (and CASA)
GarreltMellemahttp://people.su.se/~gmell/lib/exe/fetch.php?cache=cache&media=xy_100mpc_406.gif
How does the ionosphere affect PAPER
specifically?
Position vs. Time for RA and Dec
Kassim et al. 2007
VLA
How does the ionosphere affect PAPER
specifically?
Lonsdale 05
Position vs. Time for RA and Dec
Kassim et al. 2007
VLA
The Math
Condon 1997
Cohen &Rottgering 2009
Mean ~ 0.01 degreeSource size at 74 MHz ~ 0.05 deg
Mean ~ 0.03 degreeSource size at 74 MHz ~ 0.01 degLong-term effects
PAPER-16 GB
SurveyDeployCableRepeat…Calibrate… Profit!
Diagram by P. KlimaPAPER-16 GB
w/ outriggers
SurveyDeployCableRepeat…Calibrate… Profit!
Diagram by P. KlimaPAPER-16 GB
w/ outriggers
Frequency
Dependence
Sunset Transit
Source size
at 74 MHz
(VLA)
~130 MHz
PAPER-32 GB
~130 MHz
SunsetTransit
Source size
at 74 MHz
(VLA)
PAPER-32 GB
PAPER-32 continued…
VLSS
PoCo and OrbComm
CASPER
Orbcomm
Goal to empirically model such variations and see
how it affects bright source subtraction and power
spectrum detection
Labropoulos et al. 2009
Summary
• PAPER as a dedicated experiment for detecting
EoR power spectrum
• Use GB array to probe actual effects of
ionosphere on our data
• Characterize the effects on future bright source
subtraction and power spectrum detection