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Daniel R. AltschulerNAIC-Arecibo Observatory

The Arecibo Observatory is Part of NAIC which is operated by Cornell University under a cooperative agreement with the NSF

Puerto Rico

San Juan

Ponce

Mayaguez

Arecibo

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NATIONAL ASTRONOMY AND IONOSPHERE CENTER(NAIC)

Arecibo Observatory

Operated as a visitor oriented national research Facility by Cornell University under a cooperative Agreement with the National Science Foundation (NSF)

FACILITIES

- 305 m Radio Telescope

Became operational in 1963Reflector surface upgrade in 1974Gregorian upgrade 1997

Optical and Lidar Laboratory

Educational Facility

RESEARCH AREAS

Radio Astronomy ~75% (galactic and extra galactic spectroscopy, pulsars, VLBI)

Planetary Studies ~ 10% (planetary surfaces, comets, asteroids)

Space and Atmospheric Sciences ~15% (ISR, LIDAR )

OPERATION

~ 140 Permanent employees (~ 18 scientific staff)

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M31 - Andromeda

Neutral Hydrogen in galaxies1420 MHz / 21 cm

Other spectral features from interstellar molecules

Pulsars – Periods from 1.57 ms to 8.5 sec

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Centaurus A – NGC5128Radio continuum

Alt

itud

e km

Hours

Solar Maximun Solar Minimum

Incoherent Scatter Radar (430 MHz)

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Proceedings of IRENov 1958

A parabolic reflector was initially considered but later in order to be able to reach a large area of the sky it was decided to build a sphere

1959

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November 1959 – Contract signed between Cornelland AFCRL/ARPA

Why this hole in Puerto Rico?

Karst formation offers convenient holes

Need proximity to equator to observe planets

1962

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October 29, 1962

Azimuth liftMarch 4 1963

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surface

reflector

June 1963

June1963

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August 14, 1963

The original line feed was 96 feet (29 meters) long. It was built of aluminum and had a weight of about 10,000 pounds. Operated at a frequency of 430 MHz.(Now at Learning Center)

Telescope Optics I Line feeds

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1964

Nature 1965

April 7, 1964First radar echo form Mercury

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1 - NEW SURFACE (RMS < 3mm) HIGH FREQUENCY OPERATION(SPECTRAL LINE OF NEUTRAL HYDROGENAT 1420.405 MHz)

2 - NEW 2380 MHz RADAR (S-BAND).

JULY 1974 - PSR 1913+16 FIRST DETECTED(Joseph Taylor and Russell Hulse)

First upgrade

FIRST ARECIBO UPGRADE1972 - 1974

First Upgrade – New surface

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Last Panel # 38,778 - November 1973

Discovered in 1974 at Arecibo it consists of a binary neutron star system one of which pulsates towards the Earth. The reducing orbital period represents a loss of energy, which can only be accounted for by gravitational radiation.

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The orbit of the pulsar appears to rotate with time; in the diagram, notice that the orbit is not a closed ellipse, but a continuous elliptical arc whose point of closest approach (periastron) rotates with each orbit. The rotation of the pulsar's periastron is analogous to the advance of the perihelion of Mercury in its orbit. The observed advance for PSR 1913+16 is about 4.2 degrees per year. The pulsar's periastron advances in a single day by the same amount as Mercury's perihelion advances in a century.

Nature 19

7.75 h

700,000km

35,000 x Mercury

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Hulse - Taylor Nobel Prize 1993

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GREGORIAN UPGRADE 1993 –1997

1 – Ground Screen to reduce spillover noise

2 – New drive systems including active tie-downs

3 – Replace line feeds with a reflector feed system

4 – New receivers

5 – New S-band transmitter with twice the power

6 – Improve surface accuracy of reflector to reach 10 GHz

Gregorian Optics

focus

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May 16 1996

New Transmitter in Gregorian

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Gregorian receivers

Horns

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secondary

tertiary

horns

Radio pulses from a neutron star at a distance of 2000 light years in the Virgo constellation (the pulsar PSR 1257+12) provided the first evidence for an extra-solar planetary system. Alexander Wolszczandiscovered these planets in 1991 using the Arecibo radio telescope Two planets (B y C) have masses similar to Earth, and the third one (A) is like the Moon.

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Planets orbitingPulsar 1257+12

Planet D

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stamp

Radar image of Venus using Arecibo and GBTD. Campbell, L. Carter et al.

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Venus at 2 km resolution – Arecibo radar image

NEO 1999 JM 8distance 9 million km size 3 kmresolution 15 meter

1999 jm8

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Ice on the north pole of Mercury

The brighter colors show areas that reflect radar microwaves best. These regions caused great excitement when they were discovered.Astronomers believe that the shiny circles near Mercury's Poles are patches of ice in the bottoms of craters never reached by sunlight.

400x400 km; 1.5 km resolution

ALFA, operating between 1225-1525 MHz, will consist of a cluster of seven dual-polarization feeds and cooled receivers, a fiber-optical transmission system, and digital back-end signal processors. The system will enable deep surveys of, among others, new pulsars, HI in the Milky Way Galaxy and HI in external galaxies.

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Front end built by

CSRIOAustralia Telescope National Facilty

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Pulsarserches

PULSAR SURVEYS

ALFA will discover 1000 new pulsars� Understand populations

seen in radio and gamma ray bands

� Test notion that some pulsars are strange (quark) stars

� Exotic binaries

� Test theories of binary evolution

� Test fundamental physics

• Pulsar-pulsar• Pulsar-black hole

Survey simulations by J. Cordes, D. Chernoff, and Z. Arzoumanian

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HI SEARCHESSearches for galaxies in the ZOA

Searches for underluminous objects

Large scale structure

OH megamasers 0.09 < z < 0.35

FIRST RESULTS

First Pulsar

Galactic HISurvey

Ultra Deep Survey

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Maintenance

Aerial work

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understanding

Angel Ramos Foundation Visitor Center1977

Conference Center2001

FACILITIES

125,000 visitors yearIndependently funded

OPUS

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Exhibit Program

A Scale Model of the Solar System

A Day in the life of the Arecibo Observatory

More than Meets the Eye

If we keep it up we mightget rid of this pollutionin the future

Who knows…