UMCP: Zwicky Transient Facility Sees "First Light"

[bystander]

Zwicky Transient Facility Sees "First Light"
University of Maryland, College Park | 2017 Nov 14

UMD astronomers will use powerful new telescope camera for research and education

[c][attachment=0]ZTF Orion v3.jpg[/attachment][/c][hr][/hr]

A new robotic camera with the ability to capture hundreds of thousands of stars and galaxies in a single shot has taken its first image of the sky—an event astronomers refer to as "first light." The camera is the centerpiece of a new automated sky survey project called the Zwicky Transient Facility (ZTF), based at Caltech's Palomar Observatory near San Diego, California.

As partners in the ZTF effort, University of Maryland astronomers made important contributions to the planning and design of the survey project. UMD participation in ZTF is facilitated by the Joint Space-Science Institute, a partnership between UMD and NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

Every night, ZTF’s camera will scan a large swath of the Northern sky, discovering objects and events that vary in brightness over time, collectively known as transients. Survey targets will include explosive supernovae, hungry black holes, and hurtling asteroids and comets. ...

The ZTF survey is the powerful sequel to PTF. It is named after Caltech’s first astrophysicist, Fritz Zwicky, who discovered 120 supernovae in his lifetime. Recently installed at the Oschin Telescope, ZTF's new survey camera can take in seven times more sky in a single image than its predecessor. At maximum resolution, each ZTF camera image is 24,000 by 24,000 pixels—so huge that the images are difficult to display on a normal computer screen.

Additionally, ZTF's upgraded electronics and telescope drive systems enable the camera to take more than twice as many exposures every night. Astronomers will not only be able to discover more transient objects, they will also be able to catch more ephemeral features that appear and fade quickly. ...

Zwicky Transient Facility Opens Its Eyes to the Volatile Cosmos
California Institute of Technology | Palomar Observatory | 2017 Nov 14

[sallyseaver]

Wow! Thanks for this post. Good to know. The website says that one pixel is 15 microns, so does that mean that this instrument is observing in mid-infrared wavelengths? Or does the resolution of 1 pixel mean something else here?

The first thing I want to know with an astronomical image is what wave lengths I'm looking at, but this info is often buried or not offered. And how cool is it that we're going to start observing with neutrinos?!

I'm surprised to learn that an important instrument like this would be mounted in San Diego, which is NOT a high point and has light pollution. Is this for convenience to JPL?

[Chris Peterson]

Wow! Thanks for this post. Good to know. The website says that one pixel is 15 microns, so does that mean that this instrument is observing in mid-infrared wavelengths? Or does the resolution of 1 pixel mean something else here?

It is the physical size of the pixels on the detector: 15 micrometers (0.015 mm). At the focal length of the Schmidt telescope, that maps to a one arcsecond angle on the sky.

The first thing I want to know with an astronomical image is what wave lengths I'm looking at, but this info is often buried or not offered.

The detector is a typical silicon device, so its sensitivity covers the visible spectrum and near IR. The same technical page that gives the detector information also provides information on the filters used- broadband green, red, and near-IR.

And how cool is it that we're going to start observing with neutrinos?!

We've been observing neutrinos for a long time. And when neutrino detectors have picked up events, we've swung optical telescopes to those regions looking for what might have caused them. The wide field and fast response time of this new system will facilitate such dual detections.

I'm surprised to learn that an important instrument like this would be mounted in San Diego, which is NOT a high point and has light pollution. Is this for convenience to JPL?

It is because of the availability of a large aperture, low focal length telescope at Palomar. There aren't many large Schmidt telescopes in the world, and that's what you need for such a wide field camera. This is a short exposure survey camera intended to look for point source transients down only to about magnitude 20, not a deep sky imaging tool, so the amount of light pollution present at Palomar is probably not much of a problem.

[neufer]

I'm surprised to learn that an important instrument like this would be mounted in San Diego, which is NOT a high point and has light pollution. Is this for convenience to JPL?

It is because of the availability of a large aperture, low focal length telescope at Palomar. There aren't many large Schmidt telescopes in the world, and that's what you need for such a wide field camera. This is a short exposure survey camera intended to look for point source transients down only to about magnitude 20, not a deep sky imaging tool, so the amount of light pollution present at Palomar is probably not much of a problem.

The instrument is mounted in San Diego County (not city) at 5620 ft on top of Palomar Mountain in the middle of Palomar Mountain State Park. The original site was chosen during the Depression when light pollution from L.A. 90 miles away was not as much of an issue as, perhaps, other factors (; e.g., the Spanish name "Palomar" translates as "pigeon roost.")

<<Samuel Oschin (1914–July 28, 2003), born in Detroit, was a Los Angeles entrepreneur and philanthropist who was dedicated to giving back to the Los Angeles community. After a generous donation to Palomar Observatory, the 48-inch Schmidt telescope there was renamed for him. Oschin became a noted adventure traveler. He retraced Robert Peary's voyage to the North Pole, paddled up the Amazon in a dugout canoe, and crossed the Alps on an elephant following the model of Hannibal.

Oschin was born to a Jewish family on July 18, 1914 in Dayton, Ohio. At the age of ten, he started working cleaning chimneys which grew into a small business employing other boys. He never completed high school, instead working with his father who was a painter; and then took a job at Briggs manufacturing, a tool and die company in Detroit. During World War II, he and his two brothers formed their own tool and die company and won a large contract supplying airplane parts to the US Army Air Force which eventually evolved to the manufacture of bombs. After the war, he converted his factory to the manufacture of furniture to support increased demand from returning soldiers. In 1946, he moved to Los Angeles and started an air conditioning business with his brother. Seeing the demand for housing, he started a real estate development and construction company and was responsible for building one of the first planned communities in Oxnard.>>

[bystander]

UW Researchers Ready for Era of "Big Data" Astronomy
University of Washington | 2017 Nov 14

The first astronomers had a limited toolkit: their eyes. They could only observe those stars, planets and celestial events bright enough to pick up unassisted. But today’s astronomers use increasingly sensitive and sophisticated instruments to view and track a bevy of cosmic wonders, including objects and events that were too dim or distant for their sky-gazing forebears. ...

In 2016, the UW Department of Astronomy formally joined the ZTF team and will help develop new methods to identify the most “interesting” of the millions of changes in the sky — including new objects — that the ZTF will detect each night and alert scientists. ...

[sallyseaver]

The first thing I want to know with an astronomical image is what wave lengths I'm looking at, but this info is often buried or not offered.

The detector is a typical silicon device, so its sensitivity covers the visible spectrum and near IR. The same technical page that gives the detector information also provides information on the filters used- broadband green, red, and near-IR.

I looked carefully at that page. To me a "filter" is something that screens things out or only allows certain things in. I did not know that having filters of r, g and i meant optical and near-IR. Thank you for teaching me this.

And how cool is it that we're going to start observing with neutrinos?!

We've been observing neutrinos for a long time. And when neutrino detectors have picked up events, we've swung optical telescopes to those regions looking for what might have caused them. The wide field and fast response time of this new system will facilitate such dual detections.

I thought that ANTARES (acoustic detection) and KM3NeT (optical detection) are the first true neutrino observatories.

I'm surprised to learn that an important instrument like this would be mounted in San Diego, which is NOT a high point and has light pollution. Is this for convenience to JPL?

It is because of the availability of a large aperture, low focal length telescope at Palomar. There aren't many large Schmidt telescopes in the world, and that's what you need for such a wide field camera. This is a short exposure survey camera intended to look for point source transients down only to about magnitude 20, not a deep sky imaging tool, so the amount of light pollution present at Palomar is probably not much of a problem.

Good to know. Thanks

[sallyseaver]

I'm surprised to learn that an important instrument like this would be mounted in San Diego, which is NOT a high point and has light pollution. Is this for convenience to JPL?

It is because of the availability of a large aperture, low focal length telescope at Palomar. There aren't many large Schmidt telescopes in the world, and that's what you need for such a wide field camera. This is a short exposure survey camera intended to look for point source transients down only to about magnitude 20, not a deep sky imaging tool, so the amount of light pollution present at Palomar is probably not much of a problem.

The instrument is mounted in San Diego County (not city) at 5620 ft on top of Palomar Mountain in the middle of Palomar Mountain State Park. The original site was chosen during the Depression when light pollution from L.A. 90 miles away was not as much of an issue as, perhaps, other factors (; e.g., the Spanish name "Palomar" translates as "pigeon roost.")

<<Samuel Oschin (1914–July 28, 2003), born in Detroit, was a Los Angeles entrepreneur and philanthropist who was dedicated to giving back to the Los Angeles community. After a generous donation to Palomar Observatory, the 48-inch Schmidt telescope there was renamed for him. Oschin became a noted adventure traveler. He retraced Robert Peary's voyage to the North Pole, paddled up the Amazon in a dugout canoe, and crossed the Alps on an elephant following the model of Hannibal.

Oschin was born to a Jewish family on July 18, 1914 in Dayton, Ohio. At the age of ten, he started working cleaning chimneys which grew into a small business employing other boys. He never completed high school, instead working with his father who was a painter; and then took a job at Briggs manufacturing, a tool and die company in Detroit. During World War II, he and his two brothers formed their own tool and die company and won a large contract supplying airplane parts to the US Army Air Force which eventually evolved to the manufacture of bombs. After the war, he converted his factory to the manufacture of furniture to support increased demand from returning soldiers. In 1946, he moved to Los Angeles and started an air conditioning business with his brother. Seeing the demand for housing, he started a real estate development and construction company and was responsible for building one of the first planned communities in Oxnard.>>

Thank you, Art. I am interested to learn about Palomar's founding in the Depression era. I also really enjoyed learning about the agile entrepreneur Samuel Oschin, who applied his talents and insight to make enough wealth that he could contribute towards our astronomy-observing capability. The Wikipedia article about him says that he made the planetarium at Griffith Observatory possible as well -- which I think is really terrific. It's encouraging to learn about this positive human story.

[sallyseaver]

UW Researchers Ready for Era of "Big Data" Astronomy
University of Washington | 2017 Nov 14

The first astronomers had a limited toolkit: their eyes. They could only observe those stars, planets and celestial events bright enough to pick up unassisted. But today’s astronomers use increasingly sensitive and sophisticated instruments to view and track a bevy of cosmic wonders, including objects and events that were too dim or distant for their sky-gazing forebears. ...

In 2016, the UW Department of Astronomy formally joined the ZTF team and will help develop new methods to identify the most “interesting” of the millions of changes in the sky — including new objects — that the ZTF will detect each night and alert scientists. ...

I understand that it takes a long time in advance to be granted observing time for important researchers. I hope that the Univ of Washington team figures out a positive system to be responsive with so many competing demands. I'm not in the know about these things, but I bet that 300 observations per year is strong productive output. Samuel Oschin would be happy about this productivity

[Chris Peterson]

UW Researchers Ready for Era of "Big Data" Astronomy
University of Washington | 2017 Nov 14

The first astronomers had a limited toolkit: their eyes. They could only observe those stars, planets and celestial events bright enough to pick up unassisted. But today’s astronomers use increasingly sensitive and sophisticated instruments to view and track a bevy of cosmic wonders, including objects and events that were too dim or distant for their sky-gazing forebears. ...

In 2016, the UW Department of Astronomy formally joined the ZTF team and will help develop new methods to identify the most “interesting” of the millions of changes in the sky — including new objects — that the ZTF will detect each night and alert scientists. ...

I understand that it takes a long time in advance to be granted observing time for important researchers. I hope that the Univ of Washington team figures out a positive system to be responsive with so many competing demands. I'm not in the know about these things, but I bet that 300 observations per year is strong productive output. Samuel Oschin would be happy about this productivity :)

Observing time isn't granted to important researchers, it's granted to important research. Students and amateurs have received lots of time on professional instruments over the years, based on the quality of their proposals.

That said, ZTF is a survey instrument. It isn't something that people apply for time to use. It simply follows an ongoing observation program covering as much of the sky as time, weather, and location permit from Palomar. I don't know what the data usage policy will be- whether data will be immediately available to all or whether the project operators will have a short period of exclusive use. But in the long run, I'm sure it will be available to anyone (like the Hubble data). The trick is that there's so much data, without very good mining tools it will be very difficult to use productively.

[neufer]

Click to play embedded YouTube video.