A Darker View

Scientists at Keck Measure Farthest Galaxy Ever

Keck again holds the record, for the moment at least, of the farthest galaxy ever observed. It is a record that we have been passing back and forth with the neighboring Subaru Telescope for some years now. We currently have the advantage of MOSFIRE, a fantastic spectrograph to discover these objects. I expect our hold on this title will be transitory, there are candidate objects that may even be somewhat further away and back in time.

EGS-zs8-1, the farthest confirmed galaxy observed to date. Credit: NASA, ESA, P. Oesch and I. Momcheva (Yale), and the 3D-HST and HUDF09/XDF teams

Why try to observe these galaxies? They tell us a great deal about the formation of the first stars and galaxies after what astronomers call the “Dark Ages”, a period of time after the Big Bang when light could not travel through the galaxy, absorbed by a fog of neutral hydrogen. These first stars and galaxies ionized this hydrogen, creating the transparent universe we see today. By studying these galaxies we learn a great deal about how the universe we see today came to be.

W. M. Keck Observatory press release…

An international team of astronomers, led by Yale and the University of California, Santa Cruz, pushed back the cosmic frontier of galaxy exploration to a time when the Universe was only five percent of its present age. The team discovered an exceptionally luminous galaxy more than 13 billion years in the past and determined its exact distance from Earth using the powerful MOSFIRE instrument on the 10-meter Keck I telescope at the W. M. Keck Observatory in Hawaii. These observations confirmed it to be the most distant galaxy ever measured, setting a new record. The findings are being published in Astrophysical Journal Letters today.

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Lake Waiau

Our mountain is home to a wide range of geologic features, Aside from the wide range of volcanic features expected on a shield volcano, there are also glacial features and a small lake. Indeed, one could teach a fairly thorough course in geology simply visiting places on Mauna Kea. It is the lake that seems completely out of place, Lake Waiau should not exist.

The lake nestles in the crater of Puʻu Waiau, a low cinder cone on the south side of the summit at an elevation of 13,000ft (3,900m). It is not very large, about 100 yards across and about ten feet deep.

The lake is an anomaly. The cinder of Mauna Kea is highly permeable, water disappears into the ground at an impressive rate almost anywhere else on the summit. Something within the crater forms an impermeable layer that allows the water to persist at the surface.

The two most common theories are a layer of volcanic ash and/or clays, or a layer of permafrost beneath the surface. I prefer the ash and clay theory, there is suitable material present on several of the other cinder cones, most notably seen as yellow streaks down the side of Puʻu Poliʻahu and on the sides of Puʻu Waiau itself.

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Another Peek into CFHT

Upgrades. With 20 year old systems upgrading and replacing old gear is a constant job. It is even worse over at CFHT, their facility is quite a bit older than ours at Keck. Does this mean the telescope is obsolete? No way. most systems have been constantly updated with new technology. But it does take quite a bit of work…

Canada France Hawaii Telescope Upgraded TCS testing from CFHT on Vimeo.

Sunrise over the Caldera

The Sola Photo 800 Dive Light

Once you descend below a few feet underwater photographs begin to be all greens and blue. The reason is that water absorbs the red light, leaving a very skewed color balance in the images. Thus bringing a light source with you becomes important to allow the underwater world to be seen in vivid color.

I routinely use a strobe on my camera, resulting in very nice still images. But the strobe is useless for video. Thus my interest in a light that can be used as a main dive light and as a video light underwater.

Enter the Sola Photo 800 by Light and Motion… The Sola offers a nice flood with an even field of illumination for video. Several of my dive buddies use Sola lights, Thus I have had a chance to check out the lights firsthand before putting down a few hundred dollars. I was particularly noting the build quality and the control setup, both are excellent. With dozens of dives on the lights they still work well. Perhaps I should consider one of these little units?

There are several models available, but it is the photo version I was looking at. The light provides 800 lumens of white in an evenly illuminated, large field. The photo version also offers a red mode for framing and focusing that purportedly does not change the behavior of the subject. Deep red light is not seen by many marine critters as there is little to no red light at depth to be seen.

A coincidence of decent sales on the Sola lights occurring on my birthday resulted in a package appearing on my lanai. I ordered light with both the hand grip mount and with a ball mount that will allow attachment to my camera rigs.

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A Matter of Time

Time… It is simply a matter of time. At 00:00UT May 3rd, many of the observatory computers suddenly started reporting that the date was September 17th, 1995. To say that this created some problems is a dramatic understatement.

Datum TS2100 Time Servers — Two Datum TS2100 time servers installed above the telescope drive control computer (TDC)

The problem came from the primary observatory clock. This clock, properly called a time server, uses GPS signals to create a time reference that is accurate to microseconds. This is made possible by referencing to the atomic clocks carried by each GPS satellite. A time server is intricately connected to the network to distribute this time. Any computer in the building can ask it for time via the NTP protocol, but that has some inaccuracy due to network delays. For equipment requiring more precise time the server distributes a hard wired time reference using the IRIG-B protocol or a 1PPS timing pulse.

Without accurate time a telescope will simply not point in the correct direction. The calculation that the computers perform must take into account our rotating planet. Feed incorrect time to that calculation and you will point to the wrong piece of sky. A few milliseconds off can result in a pointing error of arcseconds, a large error for a large telescope.

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Halemaʻumaʻu or Dante’s Inferno?

Processing photos of the Halemaʻumaʻu lava lake presents quite the challenge. The very bright lava fountains are difficult to properly expose while showing anything of the surrounding scene. Yet another try is shown here. This version uses very heavy tonal editing to compress the dynamic range of the lava fountains while expanding the low end of the histogram to show detail in the rock walls. The result is interesting, but quite different than seen in person…

Lava Lake at Halemaʻumaʻu — The lava lake at Halemaʻumaʻu sport several fountains of lava along the far rim, May 2, 2015.

The Work of Protecting Mauna Kea

Walking into the building I saw the first sign. A prominent message placed in the windshield of a car parked by the entrance… “TMT, Too Many Telescopes” The protesters were here. I had hoped they would not be, we had things to get done in this meeting. A disruption of the meeting by protesters would mean another delay.

Too Many Telescopes — A protest sign in the window of a car outside the OMKM board meeting

The event was the regularly scheduled meeting of the Mauna Kea Management Board. The board is a group of community members who volunteer their time to the work of protecting Mauna Kea. I was here because Keck Observatory wants to install a set of new weather instruments atop our building and domes. Any change to the external appearance of the structure, however minor, requires approval of the Kahu Kū Mauna council, the Mauna Kea Management Board and the Department of Land and Natural Resources.

To that end I had written a proposal for the new instruments with a description of exactly what we wished to do. Attached is an appendix of photos and drawings to answer any possible questions. I was present to answer the inevitable questions I had not thought of and feared would get asked.

The room was filling rapidly when we arrived, far beyond the usual audience of one of these meetings. As I greeted the many people I know, I noted many new faces. They seemed out of place, a little on edge, a sense of having entered enemy territory. Many of those present were young, in their teens and early twenties, one a young mother, child carried in her arms. The t-shirts betrayed their allegiance, they came with cameras and poorly concealed protest signs.

I have no problem with those who oppose the telescopes atop Mauna Kea attending a meeting like the OMKM board meeting. Public participation is a good thing. Indeed, these meetings are open to the public for a reason, to allow anyone interested to attend and to see for themselves how those charged with managing the mountain do their jobs.

I worried about a protest that would disrupt the meeting, making it impossible to accomplish anything. This did not happen. I will give those who attended credit for showing respect for the proceedings and to those discussing the effort of caring for the mountain.

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Keck 1 AO Laser

Mercury at Maximum Elongation

Today Mercury will be at maximum eastern elongation, as high in the evening sky as it will appear for this current apparition. After today the planet will slide back into the sunset, passing through inferior conjunction on May 30th and reappearing in the dawn during the first weeks of June.

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