Wednesday, October 7, 2020

Barred Spiral Galaxy NGC 1365

Barred Spiral Galaxy NGC 1365
Click on the image for higher resolution (4.7 MB)

At around 60 million light-years from Earth, the Great Barred Spiral Galaxy NGC 1365 is captured beautifully in this image by the Hubble Space Telescope. Located in the constellation of Fornax (The Furnace), the blue and fiery orange swirls show us where stars have just formed and the dusty sites of future stellar nurseries. At the outer edge of the image, enormous star-forming regions within NGC 1365 can be seen. The bright, light-blue regions indicate the presence of hundreds of baby stars that formed from coalescing gas and dust within the galaxy's outer arms.
This Hubble image was captured as part of a joint survey with the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile. The survey will help scientists understand how the diversity of galaxy environments observed in the nearby Universe, including NGC 1365 and previous ESA/Hubble Pictures of the Week such as NGC 2835 and NGC 2775, influence the formation of stars and star clusters. Expected to image over 100 000 gas clouds and star-forming regions beyond our Milky Way, the PHANGS survey is expected to uncover and clarify many of the links between cold gas clouds, star formation and the overall shape and morphology of galaxies.
Image Credit: ESA/Hubble and NASA, J. Lee and the PHANGS-HST Team
Acknowledgement: Judy Schmidt (Geckzilla)
Image enhancement: Jean-Baptiste Faure

Saturday, October 3, 2020

Galaxy NGC 2525 and Supernova SN2018gv

Galaxy NGC 2525 and Supernova SN2018gv
Click on the image for higher resolution (5.7 MB)

Pictured here is the captivating barred spiral galaxy NGC 2525. Located nearly 70 million light-years from Earth, this galaxy is part of the constellation of Puppis in the southern hemisphere. Together with the Carina and the Vela constellations, it makes up an image of the Argo from ancient greek mythology.
Another kind of monster, a supermassive black hole, lurks at the center of NGC 2525. Nearly every galaxy contains a supermassive black hole, which can range in mass from hundreds of thousands to billions of times the mass of the Sun.
Hubble has captured a series of images of NGC 2525 as part of one of its major investigations; measuring the expansion rate of the Universe, which can help answer fundamental questions about our Universe's very nature. ESA/Hubble has now published a unique time-lapse of this galaxy and its fading supernova, clearly visible on the left in this image.
The supernova is formally known as SN2018gv and was first spotted in mid-January 2018. Supernovae like this one can be used as cosmic tape measures, allowing astronomers to calculate the distance to their galaxies.
Image Credit: ESA/Hubble and NASA, A. Riess and the SH0ES team
Acknowledgment: Mahdi Zamani
Image enhancement: Jean-Baptiste Faure

Wednesday, September 30, 2020

Emission Nebulae NGC 2014 and NGC 2020

Emission Nebulae NGC 2014 and NGC 2020
Click on the image for higher resolution (3.5 MB)

During its lifetime, the Hubble Space Telescope has captured stunning imagery and other groundbreaking data that have shown us how and where stars are born within clouds of gas. It is far from a peaceful process. The Hubble image shown on the front reveals how young, massive, energetic stars sculpt and illuminate their birthplace with powerful winds and searing ultraviolet radiation. The image is nicknamed the "Cosmic Reef", because it resembles an undersea world.
The large, red nebula (NGC 2014) and its smaller blue neighbor (NGC 2020) are part of a vast star-forming region in the Large Magellanic Cloud, a satellite galaxy of the Milky Way, approximately 163 000 light-years away. The sparkling centerpiece of NGC 2014 is a grouping of bright, hefty stars, each 10 to 20 times more massive than our Sun. The stars’ ultraviolet radiation heats the surrounding dense gas. The massive stars also unleash fierce winds of charged particles that blast away lower-density gas, forming the bubble-like structures seen on the right.
The blue areas in NGC 2014 reveal the glow of oxygen, heated to nearly 20 000 degrees Fahrenheit by the blast of ultraviolet light. The cooler, red gas indicates the presence of hydrogen and nitrogen. By contrast, the seemingly isolated blue nebula at lower left (NGC 2020) has been shaped by a solitary mammoth star. This young, massive star, called a Wolf-Rayet, has ejected its outer layers of gas, exposing its searing-hot core, making it roughly 200,000 times brighter than our Sun.
Star-forming regions generally last tens of millions of years. Star birth in this region appears to have just started, with a robust episode of newly formed stars, about 5 million years ago. The star-birth process is the same throughout the universe. Though most stars have lower masses, it is the rare massive stars, through their strong winds and energetic radiation, that shape these stellar nurseries.
The portrait features the giant nebula NGC 2014 and its neighbour NGC 2020 which together form part of a vast star-forming region in the Large Magellanic Cloud, a satellite galaxy of the Milky Way This image celebrates Hubble's 30 years of exploring the heavens.
Image Credit: NASA, ESA, and STScI
Image enhancement: Jean-Baptiste Faure

Tuesday, September 29, 2020

Intermediate Spiral Galaxy NGC 5643

Intermediate Spiral Galaxy NGC 5643
Click on the image for higher resolution (6.1 MB)

This stunning image by the Hubble Space Telescope features the spiral galaxy NGC 5643 in the constellation of Lupus (The Wolf). Looking this good isn’t easy; thirty different exposures, for a total of 9 hours observation time, together with the high resolution and clarity of Hubble, were needed to produce an image of such high level of detail and of beauty.
NGC 5643 is about 60 million light-years away from Earth and has been the host of a recent supernova event (not visible in this latest image). This supernova (2017cbv) was a specific type in which a white dwarf steals so much mass from a companion star that it becomes unstable and explodes. The explosion releases significant amounts of energy and lights up that part of the galaxy.
The observation was proposed by Adam Riess, who was awarded a Nobel Laureate in physics 2011 for his contributions to the discovery of the accelerating expansion of the Universe, alongside Saul Perlmutter and Brian Schmidt.
Image Credit: ESA/Hubble and NASA, A. Riess et al.
Acknowledgement: Mahdi Zamani
Image enhancement: Jean-Baptiste Faure

Saturday, September 26, 2020

Galaxy Cluster Abell 2744 in X-rays and visible light

Galaxy Cluster Abell 2744 in X-rays and visible light
Click on the image for higher resolution (8.1 MB)

This image is of galaxy cluster Abell 2744. Galaxy clusters are the largest objects in the universe held together by gravity. They contain enormous amounts of superheated gas, with temperatures of tens of millions of degrees, which glows brightly in X-rays, and can be observed across millions of light years between the galaxies. This image combines X-rays from the Chandra X-Ray Observatory (diffuse blue emission) with optical light data from the Hubble Space Telescope (red, green, and blue).
Image Credit: NASA/CXC; Optical: NASA/STScI
Image enhancement: Jean-Baptiste Faure

Spiral Galaxy NGC 5585

Spiral Galaxy NGC 5585
Click on the image for higher resolution (7.6 MB)

Resting on the tail of the Great Bear in the constellation of Ursa Major, lies NGC 5585, a spiral galaxy that is more than it appears. The many stars, and dust and gas clouds that make up NGC 5585, shown here in this Hubble image, contribute only a small fraction of the total mass of the galaxy. As in many galaxies, this discrepancy can be explained by the abundant yet seemingly invisible presence of dark matter.
The stellar disc of the galaxy extends over 35 000 light-years across. When compared with galaxies of a similar shape and size, NGC 5585 stands out by having a notably different composition: contributing to the total mass of the galaxy, it contains a far higher proportion of dark matter. Hotspots of star formation can be seen along the galaxy's faint spiral arms. These regions shine a brilliant blue, contrasting strikingly against the ever-black background of space.
Image Credit: ESA/Hubble and NASA, R. Tully
Acknowledgement: Gagandeep Anand
Image enhancement: Jean-Baptiste Faure

Friday, September 25, 2020

Barred Spiral Galaxy NGC 2835

Barred Spiral Galaxy NGC 2835
Click on the image for higher resolution (4.6 MB)

The twisting patterns created by the multiple spiral arms of NGC 2835 create the illusion of an eye. This is a fitting description, as this magnificent galaxy resides near the head of the southern constellation of Hydra, the water snake. This stunning barred spiral galaxy, with a width of just over half that of the Milky Way, is brilliantly featured in this image taken by the Hubble Space Telescope. Although it cannot be seen in this image, a supermassive black hole with a mass millions of times that of our Sun is known to nestle in the very center of NGC 2835.
This galaxy was imaged as part of PHANGS-HST, a large galaxy survey with Hubble that aims to study the connections between cold gas and young stars in a variety of galaxies in the local Universe. Within NGC 2835, this cold, dense gas produces large numbers of young stars within large star formation regions. The bright blue areas, commonly observed in the outer spiral arms of many galaxies, show where near-ultraviolet light is being emitted more strongly, indicating recent or ongoing star formation.
Expected to image over 100 000 gas clouds and star-forming regions outside our Milky Way, this survey hopes to uncover and clarify many of the links between cold gas clouds, star formation and the overall shape and morphology of galaxies. This initiative is a collaboration with the international Atacama Large Millimeter/submillimeter Array (ALMA) and the European Southern Observatory's Very Large Telescope's MUSE instrument, through the greater PHANGS program (PI: E. Schinnerer).
Image Credit: ESA/Hubble and NASA, J. Lee, and the PHANGS-HST Team
Acknowledgement: Judy Schmidt (Geckzilla)
Image enhancement: Jean-Baptiste Faure