The Frequency Agile Solar The Frequency Agile Solar RadiotelecopeRadiotelecope

T. S. Bastian

and the FASR Team

NRAO, NJIT, UMd, Berkeley, NSO, NRL, Obs. Paris

• FASR will be a ground based solar-dedicated radio telescope designed and optimized to produce images over a broad frequency range with

high angular, temporal, and spectral resolution

high fidelity and high dynamic range

• As such, FASR will address an extremely broad science program.

• An important goal is to mainstream solar radio observations by providing a number of standard data products for use by the wider solar physics community.

from S. Krucker’s RHESSI web pages

Nobeyama Radioheliograph

FASR FASR SpecificationsSpecifications

Frequency rangeFrequency range ~0.1-30+ GHz~0.1-30+ GHz

Frequency Frequency resolutionresolution

0.1%, 0.1 – 3 GHz0.1%, 0.1 – 3 GHz

1%, 3 – 18 GHz1%, 3 – 18 GHz

Time resolutionTime resolution 10 ms, 0.1 – 3 GHz10 ms, 0.1 – 3 GHz

100 ms, 3 – 18 GHz100 ms, 3 – 18 GHz

Number Number antennasantennas

~100 (5000 ~100 (5000 baselines)baselines)

Size antennasSize antennas LPA, 2 m, 6 mLPA, 2 m, 6 m

PolarizationPolarization Stokes I & VStokes I & V

Angular Angular resolutionresolution

20/20/ arcsec arcsec

Field of ViewField of View >0.5 deg>0.5 deg

Array configurationArray configuration

XC

“self-similar” log spiral

TRACE: 6 Nov 1999

model snapshots

10 min synth.

22 GHz22 GHz

5 GHz

Imaging

(no thermal noise)

FASR Key ScienceFASR Key Science Nature & Evolution of Coronal Magnetic FieldsNature & Evolution of Coronal Magnetic Fields Measurement of coronal magnetic fieldsMeasurement of coronal magnetic fields Temporal & spatial evolution of fieldsTemporal & spatial evolution of fields Role of electric currents in coronaRole of electric currents in corona Coronal seismologyCoronal seismology

FlaresFlares Energy releaseEnergy release Plasma heatingPlasma heating Electron acceleration and transportElectron acceleration and transport Origin of SEPsOrigin of SEPs Drivers of Space WeatherDrivers of Space Weather Birth & acceleration of CMEsBirth & acceleration of CMEs Prominence eruptionsProminence eruptions Fast solar wind streamsFast solar wind streams Relation to SEPsRelation to SEPs

from J. Lee

Active region showing strong shear: radio images show high B and very high

temperatures

from Lee et al (1998)

17 GHz intensity 17 GHz circ. pol. 34 GHz intensity

Magnetic field lines in the solar corona illuminated by gyrosynchrotron emission from nonthermal electrons.

Nobeyama RH

FASR Key ScienceFASR Key Science Nature & Evolution of Coronal Magnetic FieldsNature & Evolution of Coronal Magnetic Fields Measurement of coronal magnetic fieldsMeasurement of coronal magnetic fields Temporal & spatial evolution of fieldsTemporal & spatial evolution of fields Role of electric currents in coronaRole of electric currents in corona Coronal seismologyCoronal seismology

FlaresFlares Energy releaseEnergy release Plasma heatingPlasma heating Electron acceleration and transportElectron acceleration and transport Origin of SEPsOrigin of SEPs Drivers of Space WeatherDrivers of Space Weather Birth & acceleration of CMEsBirth & acceleration of CMEs Prominence eruptionsProminence eruptions Fast solar wind streamsFast solar wind streams Relation to SEPsRelation to SEPs

from Aschwanden & Benz 1997

from Aschwanden et al. 1992

Type U bursts observed by Phoenix/ETH and the VLA.

Two ribbon flare observed by the VLA on 17 Jun 89.

6 cm (contours)

Ha (intensity)

from Bastian & Kiplinger (1991)

FASR Key ScienceFASR Key Science Nature & Evolution of Coronal Magnetic FieldsNature & Evolution of Coronal Magnetic Fields Measurement of coronal magnetic fieldsMeasurement of coronal magnetic fields Temporal & spatial evolution of fieldsTemporal & spatial evolution of fields Role of electric currents in coronaRole of electric currents in corona Coronal seismologyCoronal seismology

FlaresFlares Energy releaseEnergy release Plasma heatingPlasma heating Electron acceleration and transportElectron acceleration and transport Origin of SEPsOrigin of SEPs Drivers of Space WeatherDrivers of Space Weather Birth & acceleration of CMEsBirth & acceleration of CMEs Prominence eruptionsProminence eruptions Fast solar wind streamsFast solar wind streams Relation to SEPsRelation to SEPs

20 April 1998

C2 C2

C3

C3

10:04:51 UT 10:31:20 UT

10:45:22 UT

11:49:14 UT

SOHO/LASCO

Bastian et al. (2001)

Noise storm

Bastian et al. (2001)

11 1.811.81 1.451.45 234234 2.5 x 102.5 x 1077 1.471.47 330330

22 0.540.54 2.052.05 218.5218.5 1.35 x 101.35 x 1077 1.031.03 265265

33 0.030.03 2.42.4 219.5219.5 6.5 x 106.5 x 1066 0.690.69 190190

44 -1.07-1.07 2.82.8 221221 5 x 105 x 1055 0.330.33 3030

LoS Rsun (deg) ne (cm-3) B(G) RT (MHz)

Maia et al 2003

15 April 2001

Nancay Radioheliograph: 421 MHz

NoRH detection of an “EIT wave” at 17 GHz: possibly the signature of the expanding edge of a coronal mass ejection at the base of the corona.

White et al 2002

FASR Science (cont)FASR Science (cont) The “thermal” solar atmosphereThe “thermal” solar atmosphere Coronal heating - nanoflaresCoronal heating - nanoflares Thermodynamic structure & dynamics Thermodynamic structure & dynamics Formation & structure of filamentsFormation & structure of filaments

Solar WindSolar Wind Birth in network Birth in network Coronal holesCoronal holes Fast/slow wind streamsFast/slow wind streams Turbulence and wavesTurbulence and waves

Synoptic studiesSynoptic studies Radiative inputs to upper atmosphereRadiative inputs to upper atmosphere Global magnetic field/dynamoGlobal magnetic field/dynamo Flare statisticsFlare statistics

Krucker et al (1997)

20 Feb 1995

“network flares”

Yohkoh SXT

VLA 2 cm

SXT

Synoptic studies

17 GHz

B gram

SXR

The FASR key science objectives are an excellent The FASR key science objectives are an excellent match to elements of SEC science goals and match to elements of SEC science goals and applications-driven LWS research.applications-driven LWS research.

To fulfill its goal of mainstreaming the use of radio To fulfill its goal of mainstreaming the use of radio imaging spectroscopy, a key project requirement imaging spectroscopy, a key project requirement is to integrate FASR data analysis and data is to integrate FASR data analysis and data products under the software umbrella used by products under the software umbrella used by relevant NASA missions and other ground based relevant NASA missions and other ground based observatories.observatories.

It is also worth exploring whether data from NASA It is also worth exploring whether data from NASA missions and other observatories could be missions and other observatories could be integrated into FASR operations in real time.integrated into FASR operations in real time.

Status and Plans

The decadal review of the NAS/NRC Astronomy and Astrophysics Survey Committee recommended an integrated suite of three ground and space based instruments designed to meet the challenges in solar physics in the coming decade. These are:

Advanced Technology Solar Telescope (O/IR)

Frequency Agile Solar Radiotelescope (radio)

Solar Dynamics Observatory (O/UV/EUV)

More recently, the decadal review of the NAS/NRC NAS/NRC Solar and Space Science Survey Committee ranked FASR as its number one priority for small projects (<$250M).

2001: Proposal to NSF Advanced Technologies and

Instrumentation program (2 years) accepted

2002-3: Design Study (NSF/ATI) underway

International Science Definition Workshop May 23-25

First FASR Technical Meeting Aug 1-2

First FASR Data Management Meeting spring, 2003

Site survey Configuration studies

Simulations Calibration strategies

Costing

2003-5: Design and Development

Prototype major elements: NSF MRI

Refine design, hardware and software

2005-9: Construction

http://www.ovsa.njit.edu/fasr

FASR CALIBRATION SUMMARYFASR CALIBRATION SUMMARYDATA PRODUCTS (maps, spectra, light curves)

- Absolute positions to <1 arcsec (10-20 GHz) - Absolute flux (and brightness temperature) calibration to ~5% - Relative (frequency to frequency) calibration to <1%

TECHNIQUES

Phase calibration: - Intrinsically stable design: simplified antenna-based electronics, temperature stabilization, buried optical fibers - Primary phase calibration against cosmic standards before/after observing day - Secondary phase calibration (troposphere, ionosphere) + geostationary satellites

+ self-calibration algorithms + other alternatives (water vapor, wave-front sensing)

Flux calibration: - Observation of known cosmic sources before/after observing day - Secondary gain monitoring using front-end noise sources

FASR DATA ACQUISITION and DATA HANDLING - 1

Observing plan

- Full disk field of view - Uninterrupted solar viewing during daylight hours (no calibration gaps) - Real-time, automated frequency- and time-dependent gain control

8 parallel signal paths from antennas (RCP and LCP for 20-300, 200-2500, 3000-12000, 12000-24000 MHz ranges)

Generation of interim database

- Programmable, but predefined correlation sequences use rapid time multiplexing of frequency bands within each range. - High spectral resolution correlation within each frequency band populates an interim database (10 Tbytes/day) which expires in ~24 hrs - Interim database has sufficient time/frequency resolution to meet all observational and frequency-excision requirements. - Time-independent calibration parameters and interference excision are applied in real-time as interim database is populated.

FASR DATA ACQUISITION and DATA HANDLING - 2

Generation of archival databases

Observing modes are implemented by flexible, parallel selection and averaging of the interim database. The archival data base will be the starting point for most data analysis.

Typical microwave databases: - Coronal magnetograms (acquired high-freq, low-time - Burst observations (acquired with high-time, freq resln) - Solar monitoring

- Campaign- or GI-driven database (TBD as requested)

- Result is a set of parallel, application-driven archival databases, generated with latency of 10 m to ~10h, to which time-dependent calibration factors have been applied. Total size: ~100 Gbyte/day

- Most archival databases will be generated automatically, but provisions will be made for manual selection of data based on quick look data and input from external sources (e.g., S/C data or other observatories)

FASR DATA ACQUISITION and DATA HANDLING - 2

Data products

Quick look products (generated with latencies of 10-60 minutes)

Light curves at microwave frequenciesBurst spectra at microwave frequencies, including preliminary maps.Dynamic spectra at metric and decimetric frequencies, (including locations and event classification)

Additional operational data products Coronal magnetic field maps (~30 minute latency) Research-oriented data products Imaging spectroscopy at metric, decimetric and microwave frequencies. Derived parameter maps (eg coronal magnetic field, temperatures,

density maps, etc.)

Context: Other Radio InitiativesContext: Other Radio Initiatives LOFARLOFAR – – a a LOLOw w FFrequency requency ARARray operating from ~20-150 ray operating from ~20-150

MHz. Presently involves MHz. Presently involves NRL, NFRA,NRL, NFRA, and and MITMIT..

EVLAEVLA – Extended – Extended VVery ery LLarge arge AArray. rray. Phase 1Phase 1 will replace will replace correlator, data Xmit, and fill out complement of Rx to correlator, data Xmit, and fill out complement of Rx to provided continuous coverage from 1-50 GHz. provided continuous coverage from 1-50 GHz. Phase 2Phase 2 will will cross-link the VLA, VLBA, and add several new elements.cross-link the VLA, VLBA, and add several new elements.

ALMAALMA – – AAtacama tacama LLarge arge MMillimeter illimeter AArray. Joint rray. Joint NRAO/ESONRAO/ESO project to build a mm/submm array of sixty-four 12 m project to build a mm/submm array of sixty-four 12 m antennas in Chile. antennas in Chile.

ATA ATA – – AAllen llen TTelescope elescope AArray, formerly the 1HT. Named for rray, formerly the 1HT. Named for sugar daddy Paul Allen, the ATA is a sugar daddy Paul Allen, the ATA is a SETI InstituteSETI Institute project. It project. It will be composed of 350 antennas of 6.1 m each and will be composed of 350 antennas of 6.1 m each and operate between 0.5-11 GHz.operate between 0.5-11 GHz.

SKA SKA – – SSquare quare KKilometer ilometer AArray. Next big thing. Large rray. Next big thing. Large international consortium. Won’t happen for >10 yrsinternational consortium. Won’t happen for >10 yrs..

None of the above is solar dedicated