research talk for ursi

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