Hubble and Chandra Discover Dark Matter Is Not as Sticky as Once Thought
In particle physics labs, like the Large Hadron Collider in Geneva, Switzerland,
scientists smash atoms together to study the underpinnings of matter and energy.
On the scale of the macrocosm, nature provides a similar experiment by crashing
clusters of galaxies together. Besides galaxies and gas, the galaxy clusters
contain huge amounts of dark matter. Dark matter is a transparent form of matter
that makes up most of the mass in the universe. During collisions, the clouds of
gas enveloping the galaxies crash into each other and slow down or stop.
Astronomers found that the dark matter continued straight through the violent
collisions, without slowing down relative to the galaxies. Their best explanation
is that the dark matter did not interact with visible particles, and it also
interacted less frequently with other dark matter than previously thought.
Astronomers used the Hubble Space Telescope and Chandra X-ray Observatory to study
72 large galaxy cluster collisions. Chandra traced the hot gas, and Hubble saw
how the invisible dark matter warps space and distorts the images of background
stars. This allowed for the distribution of dark matter in the collision to be
mapped. The finding narrows down the options for what this dark matter might be.
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Cycle 23 Call for Proposals
NASA and The Space Telescope Science Institute (STScI) are pleased to announce the Cycle 23 Call for Proposals for Hubble Space Telescope (HST) Observations and funding for Archival Research and Theoretical Research programs. Participation in this program is open to all categories of organizations, both domestic and foreign, including educational institutions, profit and nonprofit organizations, NASA Centers, and other Government agencies.
This solicitation for proposals will be open through April 10, 2015 8:00pm EDT. The Astronomer's Proposal Tools (APT), which is required for Phase I Proposal Submission will be made available/released for Cycle 23 Phase I use during the 2nd week of February 2015. Results of the selection will be announced by the end of June 2015.
Hangouts and Town Halls at the AAS January 5-8
Daily 3:30-5:00 Hubble Hangout with one special highlight of the day and a daily recap
AAS Town Halls will be recorded and posted on YouTube and Google+.
Hubble’s 2020 Vision
The Hubble Space Telescope (HST) was launched in 1990 and will shortly celebrate its 25th anniversary. During that time, it has revolutionized diverse fields spanning the full gamut of astronomical research. Hubble’s last servicing mission, SM4, occurred in May 2009 when the Cosmic Origins Spectrograph and Wide-Field Camera 3 were installed, and the Advanced Camera for Surveys and the Space Telescope Imaging Spectrograph were refurbished. The guiding philosophy in planning SM4 was to maximize the scientific return from HST over the 5 year period following the servicing mission. Since then, Hubble has pushed the observational frontier to ever greater depths in the high-redshift Universe, dissected the stellar populations of star systems in the Milky Way and nearby galaxies, probed the composition of gaseous galactic halos and applied novel scanning techniques to probe exoplanet atmospheres and achieve Gaia-like relative astrometric accuracies.
Hubble remains in prime condition with top-flight instrumentation. NASA has formally analyzed system lifetimes and finds that the observatory should continue to operate through the end of the decade. Now is therefore the time to set priorities for the next 5 years, keeping in mind that this period of time will include overlap with the James Webb Space Telescope, which is scheduled to launch in late 2018. Following extensive discussions with the Space Telescope User Committee (STUC), we are soliciting direct input from the community to aid us in determining how best to structure the next five years of Hubble observations.
Call for White Papers
We solicit brief white papers from the community describing initiatives that will enhance significantly Hubble’s scientific legacy from the next 5 years of observations. These papers, which must have a length of no more than 3 pages, can address any aspect of the Hubble program. For example,
- JWST will be launched in 2018. Are there specific programs that Hubble should undertake now in preparation for that launch, or during the period of overlapping observations, that take advantage of Hubble's unique capabilities? What types of synergistic observations should be included in our plans?
- Are there observations from other ground- or space-based observatories that should be more closely linked to Hubble observations over the next few years?
- Are there specific science questions that should receive greater emphasis over the next five years? If so, why?
- Should Hubble devote a greater proportion of observing time to specific demographics (e.g., ph.d. thesis students)?
- Transient phenomena and the variable universe represent a growing focus of astronomical research with the development of large-scale synoptic surveys such as the Palomar Transit Factory, Pan-STARRs and its descendants and, eventually, the Large Synoptic Survey Telescope. Should HST make a special effort to optimize its observational program for those phenomena? If so, how?
- Given that Hubble's lifetime is finite, are there changes to the time allocation process that should be made to encourage or enable quicker response to new discoveries?
White papers should summarize the anticipated science objectives, conveying a sense of their import, urgency, and timeliness. They should explain why those objectives cannot be accomplished under the present time allocation system. White papers should also include a preliminary assessment of feasibility of the proposed changes.
THE DEADLINE FOR THE SUBMISSION OF WHITE PAPERS IS MARCH 4, 2015.
White paper authors should assume that the readers are knowledgeable and should not devote time or space to a lengthy introduction or background information. If you are aware of any special observing constraints associated with your suggestion, please outline those constraints in your white paper.
The white papers will be reviewed by a small advisory committee including the Head of the HST Mission Office, Ken Sembach, the Head of the Science Mission Office, Neill Reid, and representatives from the Space Telescope Users Committee. All submissions will be held confidential. The committee will make its recommendation to the Director within 6 weeks of the white paper deadline, and those recommendations will be discussed with the STUC at its April 16-17, 2015 meeting.
White Paper Submission Process
White papers should be submitted as pdf files via e-mail to: firstname.lastname@example.org and copied to Neill Reid (email@example.com). Each submission will be acknowledged within 3 days. If no acknowledgement is received within that time period, please inform us via e-mail.
Questions about this notification should be addressed to firstname.lastname@example.org, copying email@example.com.
HST Frontier Fields
Using Director's Discretionary (DD) observing time, HST is undertaking a revolutionary deep field observing program to peer deeper into the Universe than ever before and provide a first glimpse of JWST's universe. These Frontier Fields will combine the power of HST with the natural gravitational telescopes of high-magnification clusters of galaxies. Using both the Wide Field Camera 3 and Advanced Camera for Surveys in parallel, HST will produce the deepest observations of clusters and their lensed galaxies ever obtained, and the second-deepest observations of blank fields (located near the clusters). These images will reveal distant galaxy populations ~10 - 100 times fainter than any previously observed, improve our statistical understanding of galaxies during the epoch of reionization, and provide unprecedented measurements of the dark matter within massive clusters.
Data releases of the already observed clusters are available at the MAST Frontier Fields website.
The Frontier Fields public lensing models have been released and are available on the MAST Frontier Fields Lensing Model website. This website includes interactive tools for examining the lensing maps and obtaining magnifications and uncertainties from a variety of models, given a position and redshift.
For more information about the survey, please see the Frontier Fields website.
Exposure Time Calculators
The ETCs are web-based applications that assist Hubble users in preparing Phase I and Phase II observing proposals. The ETCs calculate exposure times or SNRs for simulated astronomical observations using any of HST's primary instruments:
ACS | COS | STIS | WFC3
Hubble Legacy Archive
The Hubble Legacy Archive (HLA) is designed to optimize science from HST by providing online, enhanced Hubble products and advanced browsing capabilities.