galaxy – Page 2 – A Darker View

Milky Way Gallery

Horizon panorama from Ka'ohe, on the side of Mauna Kea — Horizon panorama from Ka’ohe, on the side of Mauna Kea

The Inkblot — The cluster NGC6520 and the dark nebula B86 lost in the immensity of Baade’s Window

Milky Way Dawn over Mauna Loa — The rising summer Milky Way, Mars and dawn over Mauna Loa

MIlky Way over A'a — The rising Milky Way silhouetting and old a’a lava flow on Mauna Kea, Canon 60D @ ISO12800, 17mm f/4, eight 10 second frames aligned and averaged

Baade's Window — Baade’s Window, single 8 minute exposure at ISO 800, Canon 20Da DSLR camera mounted on a Televue-76 APO telescope with a 0.8x focal reducer/field flattener

Milky Way over Mauna Loa — A bright summer Milky Way shines over Mauna Loa

Dual Lasers on the Galactic Center — Both Keck lasers aimed at the center of the Milky Way galaxy

VLBA & Milky Way — The summer Milky Way soars over the VLBA antenna atop Mauna Kea

Lagoon and Trifid Nebulae — The Lagoon, M8 and the Trifid, M20 nebulae in Sagittarius

M9 and B64 — The globular cluster M9 next to the dark nebulae B64

The central Milky Way from Mauna Kea, 37 x 30sec, Canon 6D w/24-105mm- f/4.5 @ ISO6400

Summit and Winter Milky Way — The winter Milky Way over the summit of Mauna Kea, Canon 6D and Samyang 14mm f/2.8 lens, 30s at ISO 6400

Three Strikes — Three AO lasers aimed at the center of our Milky Way galaxy, the lasers are from both Keck 1 and Keck 2 as well as the Subaru telescope

Milky Way over Pu'u Huluhulu — Venus and the summer Milky Way rising over Pu’u Huluhulu

Lasers Across the Milky Way — The Keck 2 and Subaru lasers cross the Milky Way above Mauna Kea

The Snake Nebula — B72, the Snake Nebula, single 8 minute exposure at ISO 800, Canon 20Da DSLR camera mounted on a Televue-76 APO telescope with a 0.8x focal reducer/field flattener

Astronomers Measure Universe Expansion, Get Hints of ‘New Physics’

W. M. Keck Observatory press release…

Astronomers have just made a new measurement of the Hubble constant, the rate at which the universe is expanding, and it doesn’t quite line up with a different estimate of the same number. That discrepancy could hint at “new physics” beyond the standard model of cosmology, according to the team, which includes physicists from the University of California, Davis, that made the observation.

Lensed Quasar HE0435-1223 — The image of this quasar is split into four by a massive galaxy acting as a gravitational lens. Image credit: Sherry Suyu, European Space Agency/Hubble Space Telescope/NASA

The Hubble constant allows astronomers to measure the scale and age of the universe and measure the distance to the most remote objects we can see, said Chris Fassnacht, a physics professor at UC Davis and a member of the international H0LiCOW (H0 Lenses in COSMOGRAIL’s Wellspring) collaboration, which carried out the work.

Led by Sherry Suyu at the Max Planck Institute for Astrophysics in Germany, the H0LICOW team used the NASA/ESA Hubble Space Telescope and other space- and Earth-based telescopes, including the Keck telescopes in Hawaii, to observe three galaxies and arrive at an independent measurement of the Hubble constant. Eduard Rusu, a postdoctoral researcher at UC Davis, is first author on one of five papers describing the work, due to be published in the Monthly Notices of the Royal Astronomical Society.

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Universe Gallery

Comet C/2013 R1 Lovejoy on Nov 15, 2013. Canon 6D with the AT6RC and a 0.8x focal reducer. 12 x 60s at ISO 6400.

Double Cluster — The open clusters NGC869 and NGC884 in Perseus, 20x240s exposures Canon 20Da and TV-76mm

The Rosette Nebula, NGC2237, NGC2238, NGC2244, NGC2246, Canon 6D and TV-76mm, 10x240s+10x60s+10x15s @ISO6400

M22 or NGC6656 in Sagittarius, a classic globular cluster, AT6RC and Canon 60D 20x4min @ ISO2000

144P/Kushida — Comet 144P Kushida passing through heavy starfield in Taurus on the evening of 15 Feb 2009, stack of 10 x 4min exposures with a Canon 20Da and TV-76mm

The Pleiades, M45, a sum of 26 x 100s luminance frames and 5 x 100s RGB images assembled as an LRGB image, ST2K and 80mm APO

Markarian's Chain — The galaxies of the Virgo Cluster, including M84, M86 and M87, Canon 6D and TV-76mm, 10x240s+10x60s+10x15s

The Orion Nebula — NGC1976 or M42, the Great Orion Nebula, sum of 113 frames at 35x5min, 38x1min, 20x20sec, and 20x5sec. Taken with the Canon 20Da and a AT6RC telescope.

The galaxies M81 & M82 with SN2014J seen in the disk M82 at top

Comet C/2007 N3 Lulin on the evening of 26 Feb 2009, a stack of 10 x 4 min exposures, Canon 20Da and TeleVue 76mm APO

M42, The Orion Nebula, Canon 6D and TV-76mm, 16x240s+10x60s+10x15s @ISO6400

M46 & NGC2438 — The open cluster M46 and the planetary nebula NGC2438 in Puppis, 32 x 1min exposures with the AT6RC and Canon 20Da

Omega Centauri, NGC5139, sum of 31 x 1min exposures, AT6RC and Canon 60D

Galactic Center — The galactic center region on the Sagittarius-Scorpius border

M6 The Butterfly Cluster — M6, the Butterfly Cluster, 9 x 1min Canon 60D and AT6RC

Scientists Discover Massive Galaxy Made of 99.99 Percent Dark Matter

W. M. Keck Observatory press release…

Using the world’s most powerful telescopes, an international team of astronomers has discovered a massive galaxy that consists almost entirely of Dark Matter. Using the W. M. Keck Observatory and the Gemini North telescope – both on Maunakea, Hawaii – the team found a galaxy whose mass is almost entirely Dark Matter. The findings are being published in The Astrophysical Journal Letters today.

Even though it is relatively nearby, the galaxy, named Dragonfly 44, had been missed by astronomers for decades because it is very dim. It was discovered just last year when the Dragonfly Telephoto Array observed a region of the sky in the constellation Coma. Upon further scrutiny, the team realized the galaxy had to have more than meets the eye: it has so few stars that it quickly would be ripped apart unless something was holding it together.

To determine the amount of Dark Matter in Dragonfly 44, astronomers used the DEIMOS instrument installed on Keck II to measure the velocities of stars for 33.5 hours over a period of six nights so they could determine the galaxy’s mass. The team then used the Gemini Multi-Object Spectrograph (GMOS) on the 8-meter Gemini North telescope on Maunakea in Hawaii to reveal a halo of spherical clusters of stars around the galaxy’s core, similar to the halo that surrounds our Milky Way Galaxy.

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Cosmic Neighbors Inhibit Star Formation, Even in the Early-Universe

W. M. Keck Observatory press release…

Galaxy cluster MACS J0416 — Massive galaxy cluster MACS J0416 seen in X-rays (blue), visible light (red, green, and blue), and radio light (pink). Credit: NASA, CXC, SAO, G.Ogrean, STSCI, NRAO, AUI, NSF

The international University of California, Riverside-led SpARCS collaboration has discovered four of the most distant clusters of galaxies ever found, as they appeared when the Universe was only four billion years old. Clusters are rare regions of the Universe consisting of hundreds of galaxies containing trillions of stars, as well as hot gas and mysterious Dark Matter. Spectroscopic observations from the W. M. Keck Observatory on Maunakea, Hawaii and the Very Large Telescope in Chile confirmed the four candidates to be massive clusters. This sample is now providing the best measurement yet of when and how fast galaxy clusters stop forming stars in the early Universe.

“We looked at how the properties of galaxies in these clusters differed from galaxies found in more typical environments with fewer close neighbors,” said lead author Julie Nantais, an assistant professor at the Andres Bello University in Chile. “It has long been known that when a galaxy falls into a cluster, interactions with other cluster galaxies and with hot gas accelerate the shut off of its star formation relative to that of a similar galaxy in the field, in a process known as environmental quenching. The SpARCS team have developed new techniques using Spitzer Space Telescope infrared observations to identify hundreds of previously-undiscovered clusters of galaxies in the distant Universe.”

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UCLA Astronomers Use Keck Observatory to Look Back 12 Billion Years and Measure Oxygen

W. M. Keck Observatory press release…

UCLA astronomers have used the W. M. Keck Observatory on Maunakea, Hawaii to make the first accurate measurement of the abundance of oxygen in a distant galaxy. Oxygen, the third-most abundant chemical element in the Universe, is created inside stars and released into interstellar gas when stars die. Quantifying the amount of oxygen is key to understanding how matter cycles in and out of galaxies. This research is published online in the Astrophysical Journal Letters.

“This is by far the most distant galaxy for which the oxygen abundance has actually been measured,” said Alice Shapley, a UCLA professor of astronomy, and co-author of the study. “We’re looking back in time at this galaxy as it appeared 12 billion years ago.”

Knowing the abundance of oxygen in the galaxy called COSMOS-1908 is an important stepping stone toward allowing astronomers to better understand the population of faint, distant galaxies observed when the Universe was only a few billion years old, Shapley said.

COSMOS-1908 contains approximately one billion stars. In contrast, the Milky Way contains approximately 100 billion stars. Furthermore, COSMOS-1908 contains approximately only 20 percent the abundance of oxygen that is observed in the Sun.

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Faintest Early-Universe Galaxy Ever, Detected and Confirmed

W. M. Keck Observatory press release…

An international team of scientists has detected and confirmed the faintest early-Universe galaxy ever using the W. M. Keck Observatory on the summit on Maunakea, Hawaii. In addition to using the world’s most powerful telescope, the team relied on gravitational lensing to see the incredibly faint object born just after the Big Bang. The results are being published in The Astrophysical Journal Letters today.

MACS2129.4-0741 — Color image of the cluster taken with Hubble Space Telescope (images in three different filters were combined to make an RGB image). Credit: Bradac/HST/W. M. Keck Observatory

The team detected the galaxy as it was 13 billion years ago, or when the Universe was a toddler on a cosmic time scale.

The detection was made using the DEIMOS instrument fitted on the ten-meter Keck II telescope, and was made possible through a phenomenon predicted by Einstein in which an object is magnified by the gravity of another object that is between it and the viewer. In this case, the detected galaxy was behind the galaxy cluster MACS2129.4-0741, which is massive enough to create three different images of the object.

“Keck Observatory’s telescopes are simply the best in the world for this work,” said Marusa Bradac, a proefssor at University of California, Davis who led the team. “Their power, paired with the gravitational force of a massive cluster of galaxies, allows us to truly see where no human has seen before.”

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Dual Lasers on the Galactic Center

I have been trying to get some good photos of both Keck lasers on the galactic center for some years. Other photographers have produced spectacular photos that have me seething with envy. Why can I not get equivalent photos? It is not like I have a lack of access. The answer is mostly bad luck and circumstance. I do work, this limits the nights I can make the attempt. On those times I have ascended the mountain to photograph I have been plagued by bad weather.

There are only a few nights a year when Andrea Ghez and the UCLA Galactic Center Group have both telescopes scheduled, the night when both lasers will be focused on the core of our galaxy and the massive black hole that dwells there. Last year I had attempted a night only to find clouds and fog through the night allowing only a few moments of dual lasers and disappointing results.

This year looked to be much the same. The night was set, I had volunteered to host several local photographers, we had film permits on-hand, an observatory vehicle reserved, all the arrangements made. The only issue? The Mauna Kea Weather Center forecast promised high clouds and fog for the night. I was bracing for yet another disappointment.

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Metal Content in Early Galaxies Challenges Star Forming Theory

W. M. Keck Observatory press release…

An International team led by scientists at ETH Zurich in Switzerland used the W. M. Keck Observatory to study the role of star formation rates in metal contents of distant galaxies. What they discovered is the amount of metals are very similar, irrespective of galaxies’ star formation activity, raising new questions about star-forming theory. Their findings were recently published in the Astrophysical Journal.

Heavy Elements — A galaxy observed in this study (surrounded by a blue rectangle). The light we received from the galaxy in the distant Universe tells us – from hydrogen, oxygen, and neon emission lines – that they followed a different rule to produce the heavy elements. Credit: 3D-HST / NASA / ESA / STSCI

Using the MOSFIRE instrument installed on the Keck I telescope – one of the two world’s largest optical telescopes at Keck Observatory – the scientists gathered data on 41 normal, star-forming galaxies that were 11 billion light years away.

The team found typical galaxies forming stars in the Universe two billion years after the Big Bang have only twenty percent of metals (elements heavier than Helium) compared with those in the present day Universe. They also discovered the metal content is independent of the strength of the star-formation activity – in stark contrast with what is known for recently formed, or nearby galaxies.

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New Hypervelocity Binary Star Challenges Dark Matter, Stellar Acceleration Models

W. M. Keck Observatory press release…

A team of astronomers at the Friedrich Alexander University led by Péter Németh has discovered a binary star moving nearly at the escape velocity of our galaxy. There are about two dozen so-called hypervelocity stars known to be escaping the galaxy. While all of them are single stars, PB3877 is the first wide binary star found to travel at such a high speed. Additionally, the results of the new study challenge the commonly accepted scenario that hypervelocity stars are accelerated by the supermassive black hole at the galactic center. The findings are being published in the Astrophysical Journal Letters today.

PB3877 Binary — PB3877 is a hyper-velocity wide binary star zooming through the outskirts of the Milky Way galaxy. This image shows its current location as well as our Sun.

The team, in collaboration with researchers from the California Institute of Technology, showed the binary cannot originate from the Galactic Center, and no other mechanism is known that is able to accelerate a wide binary to such a high velocity without disrupting it. They therefore hypothesized there must be a lot of dark matter to keep the star bound to the Milky Way galaxy; or the binary star, PB3877, could be an intruder that has been born in another galaxy and may or may not leave the Milky Way again.

PB3877 was first reported to be a hyper-velocity, hot compact star, when it was discovered form the Sloan Digital Sky-Survey (SDSS) data in 2011. New spectroscopic observations were done with the 10 meter Keck II telescope at W. M. Keck Observatory on Maunakea, Hawaii and with the 8.2 meter Very Large Telescope (VLT) of the European Southern Observatory (ESO) in Chile.Caltech astronomers Thomas Kupfer and Felix Fürst observed PB3877 with the ESI Instrument fitted on the Keck II telescope.

“When we looked at the new data, much to our surprise, we found weak absorption lines that could not come from the hot star,” Kupfer said. “The cool companion, just like the hot primary, shows a high radial velocity. Hence, the two stars form a binary system, which is the first hyper-velocity wide binary candidate.”

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