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Supermassive black holes haunt the cores of many galaxies. Yet for all we know about black holes (not nearly enough!), the big ones remain a mystery, particularly when they began forming. Interestingly, astronomers see them in the early epochs of cosmic history. That raises the question: how did they get so big when the Universe was still just a baby?

A team of astronomers in Taiwan is looking for answers. Led by Chi-Hong Lin and Ke-Jung Chen from Academia Sinica and Chorng-Yuan Hwang of National Central University, the team is researching formation theories for supermassive black holes (SMBH). They’ve used sophisticated models of galaxy mergers to take a peek at the formation of these monsters and included giant molecular clouds as part of the process. “Our research results can offer people a deeper understanding of galaxy evolution,” Lin said. “We anticipate that there will be more observational results to verify our conclusion.”

Giant Molecular Clouds and SMBH

The team suggests that the growth of black holes in early galaxies primarily occurs through the accretion of those molecular clouds during mergers. Thanks to the gravitational forces at work these massive clouds fall to the galactic center very efficiently. That increases the formation rate of stars in the galaxy and provides the building blocks for the rapid growth of a central SMBH.

The idea of collapsing molecular clouds is not a new one. Earlier papers suggested the idea, but this work models their quick growth. It shows that black holes of a few million solar masses can grow to billions of solar masses within a few hundred million years. That helps explain why we see SMBH so early in cosmic history.

Supermassive Black Holes and Mergers

Understanding the formation of SMBH in galaxy cores is one of astronomy’s challenges. These monsters can grow to contain millions or billions of solar masses. And, you might be forgiven if you assume that something that massive would take billions of years to form. After all, a galaxy needs at least that much mass—and a lot more—to sustain such a monster at its heart. Mergers of galaxies take place on timescales that range up to millions of years.

The Mice Galaxies (NGC 4676) are famous interacting galaxies currently undergoing a process of collision and merger. The long tail on the right side is a result of the gravitational tidal forces during the merging process. When galaxies merge, a significant amount of  molecular gas flows into the central region, promoting the formation of numerous stars and facilitating the growth of supermassive black holes. Image Credit: NASA, H. Ford (JHU), G. Illingworth (UCSC/LO), M.Clampin (STScI), G. Hartig (STScI), the ACS Science Team, and ESA.
The Mice Galaxies (NGC 4676) are currently undergoing a process of collision and merger. When galaxies merge, a lot of molecular gas flows into the central region, promoting star formation and facilitating the growth of supermassive black holes. Image Credit: NASA, H. Ford (JHU), G. Illingworth (UCSC/LO), M.Clampin (STScI), G. Hartig (STScI), the ACS Science Team, and ESA.

For example, the galaxies in the Mice collision (above) are partway through their merger. The Milky Way and Andromeda are in the earliest stages of a collision that will take perhaps 7 or 8 billion years to complete. Their central black holes will merge, too.

Astronomers have known since the late 1960s that most galaxies have SMBH in their cores and that they’re somehow associated with their host galaxies. Research seems to correlate the mass of the black hole to a galaxy’s bulge, stellar mass, and other characteristics. Further research also suggested that it took time for all this accretion to a black hole to take place.

So, imagine everyone’s surprise when they started finding them in galaxies lying more than 12 billion light-years away. That puts them at a time in cosmic history when the Universe was not quite a billion years old. How could this happen? That’s where the simulations of massive clouds of gas in galaxies come into play.

Invoking New Models of Supermassive Black Hole Formation

The team in Taiwan created simulations of merging galaxies in an effort to explain the rapid growth of SMBH in the early Universe. They had to take into account different kinds of mergers, including gas-rich and gas-poor galaxies and minor mergers. They also took into account those giant

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How to Backpack the Teton Crest Trail Without a Permit

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By Michael Lanza

So you just got the inspired idea to backpack the Teton Crest Trail and discovered you’re months late to reserve a backcountry permit. You’ve probably also learned that it’s possible to get a walk-in backcountry permit for Grand Teton National Park—but competition for those is high, especially for the camping zones along the TCT.

So you’re wondering: Is it possible to backpack the Teton Crest Trail without a permit? In a word, the answer is: yes. It’s somewhat complicated and not easy, but this story explains how to do that.

The Teton Crest Trail deservedly sees sky-high demand for backcountry permits. It’s unquestionably one of the 10 best backpacking trips in America, incredibly scenic virtually every step from start to finish, featuring high passes with sweeping vistas, endless meadows bursting with wildflowers, beautiful lakes, creeks, and waterfalls, a good chance of seeing wildlife like elk and moose—and some of the best campsites you will ever pitch a tent in.

Tet19 047 Me on Teton Crest Trail copy cropped 37
Hi, I’m Michael Lanza, creator of The Big Outside. Click here to sign up for my FREE email newsletter. Join The Big Outside to get full access to all of my blog’s stories. Click here for my e-books to classic backpacking trips. Click here to learn how I can help you plan your next trip.

Backpackers on the Teton Crest Trail on Death Canyon Shelf, Grand Teton National Park.
” data-image-caption=”Backpackers on the Teton Crest Trail on Death Canyon Shelf, Grand Teton National Park. Click photo for my expert e-book to backpacking the Teton Crest Trail.
” data-medium-file=”https://i0.wp.com/tbo-media.sfo2.digitaloceanspaces.com/wp-content/uploads/2020/03/06231051/Tet19-018-Backpackers-on-the-Teton-Crest-Trail-Death-Canyon-Shelf-Grand-Teton-N.P..jpg?fit=300%2C200&ssl=1″ data-large-file=”https://i0.wp.com/tbo-media.sfo2.digitaloceanspaces.com/wp-content/uploads/2020/03/06231051/Tet19-018-Backpackers-on-the-Teton-Crest-Trail-Death-Canyon-Shelf-Grand-Teton-N.P..jpg?fit=900%2C600&ssl=1″ src=”https://i0.wp.com/tbo-media.sfo2.digitaloceanspaces.com/wp-content/uploads/2020/03/06231051/Tet19-018-Backpackers-on-the-Teton-Crest-Trail-Death-Canyon-Shelf-Grand-Teton-N.P.-1024×683.jpg?resize=900%2C600&ssl=1″ alt=”Backpackers on the Teton Crest Trail on Death Canyon Shelf, Grand Teton National Park.” class=”wp-image-38603″ srcset=”https://tbo-media.sfo2.digitaloceanspaces.com/wp-content/uploads/2020/03/06231051/Tet19-018-Backpackers-on-the-Teton-Crest-Trail-Death-Canyon-Shelf-Grand-Teton-N.P..jpg 1024w, https://tbo-media.sfo2.digitaloceanspaces.com/wp-content/uploads/2020/03/06231051/Tet19-018-Backpackers-on-the-Teton-Crest-Trail-Death-Canyon-Shelf-Grand-Teton-N.P..jpg 300w, https://tbo-media.sfo2.digitaloceanspaces.com/wp-content/uploads/2020/03/06231051/Tet19-018-Backpackers-on-the-Teton-Crest-Trail-Death-Canyon-Shelf-Grand-Teton-N.P..jpg 768w, https://tbo-media.sfo2.digitaloceanspaces.com/wp-content/uploads/2020/03/06231051/Tet19-018-Backpackers-on-the-Teton-Crest-Trail-Death-Canyon-Shelf-Grand-Teton-N.P..jpg 1080w, https://tbo-media.sfo2.digitaloceanspaces.com/wp-content/uploads/2020/03/06231051/Tet19-018-Backpackers-on-the-Teton-Crest-Trail-Death-Canyon-Shelf-Grand-Teton-N.P..jpg 1200w” sizes=”(max-width: 900px) 100vw, 900px” data-recalc-dims=”1″ />Backpackers on the Teton Crest Trail on Death Canyon Shelf, Grand Teton National Park. Click photo for my expert e-book to backpacking the Teton Crest Trail.

I’ve taken at least 20 trips in the Tetons and several on the Teton Crest Trail over the past three decades, including the 10 years I spent as Northwest Editor of Backpacker magazine and even longer running this blog.

See my story about my most-recent TCT trip, “A Wonderful Obsession: Backpacking the Teton Crest Trail,” which requires a paid subscription to

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Backpacking the Teton Crest Trail—A Photo Gallery

Tet19 047 Me on Teton Crest Trail copy cropped 34

By Michael Lanza

As we hiked up the North Fork of Cascade Canyon on the Teton Crest Trail in Grand Teton National Park, moments after the path emerged from the forest into a meadow strewn with boulders and still dappled with blooming wildflowers in late August, my friend David turned to look over his shoulder and blurted out, “Oh, wow, look at that view!” Behind us, the sheer north faces of the Grand Teton and Mount Owen towered a vertical mile above us, shooting straight up over the canyon like fireworks (photo above).

By that point on our trip, though, uncontrolled outbursts of awe were occurring several times a day. That’s what it’s like to backpack the Teton Crest Trail.

Tet19 047 Me on Teton Crest Trail copy cropped 35
Hi, I’m Michael Lanza, creator of The Big Outside. Click here to sign up for my FREE email newsletter. Join The Big Outside to get full access to all of my blog’s stories. Click here for my e-books to classic backpacking trips. Click here to learn how I can help you plan your next trip.

A backpacker on the Teton Crest Trail in Grand Teton National Park.
” data-image-caption=”Jeff Wilhelm backpacking the Teton Crest Trail in Grand Teton National Park. Click photo for my e-book “The Complete Guide to Backpacking the Teton Crest Trail.”
” data-medium-file=”https://i0.wp.com/tbo-media.sfo2.digitaloceanspaces.com/wp-content/uploads/2019/09/06232037/DSC_2401.jpg?fit=300%2C200&ssl=1″ data-large-file=”https://i0.wp.com/tbo-media.sfo2.digitaloceanspaces.com/wp-content/uploads/2019/09/06232037/DSC_2401.jpg?fit=900%2C599&ssl=1″ src=”https://i0.wp.com/tbo-media.sfo2.digitaloceanspaces.com/wp-content/uploads/2019/09/06232037/DSC_2401-1024×681.jpg?resize=900%2C599&ssl=1″ alt=”A backpacker on the Teton Crest Trail in Grand Teton National Park.” class=”wp-image-35224″ srcset=”https://tbo-media.sfo2.digitaloceanspaces.com/wp-content/uploads/2019/09/06232037/DSC_2401.jpg 1024w, https://tbo-media.sfo2.digitaloceanspaces.com/wp-content/uploads/2019/09/06232037/DSC_2401.jpg 300w, https://tbo-media.sfo2.digitaloceanspaces.com/wp-content/uploads/2019/09/06232037/DSC_2401.jpg 768w, https://tbo-media.sfo2.digitaloceanspaces.com/wp-content/uploads/2019/09/06232037/DSC_2401.jpg 1080w, https://tbo-media.sfo2.digitaloceanspaces.com/wp-content/uploads/2019/09/06232037/DSC_2401.jpg 1200w” sizes=”(max-width: 900px) 100vw, 900px” data-recalc-dims=”1″ />Jeff Wilhelm backpacking the Teton Crest Trail in Grand Teton National Park. Click photo for my e-book “The Complete Guide to Backpacking the Teton Crest Trail.”

Three friends and I backpacked a 36-mile traverse of Grand Teton National Park, mostly on the Teton Crest Trail, in late August—in many ways, an ideal time to hike there. While I’ve backpacked the TCT several times now, it was the first time for all three of them.

Seeing the reactions of these friends—every one of them very experienced backpackers who’ve taken numerous trips with me—to the scenery along this classic trek, reaffirmed my opinion that few multi-day hikes offer so much grandeur almost every step of way like the Teton Crest Trail. But I’ll let the photos in this story make that case.

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A backpacker on the Teton Crest Trail in Grand Teton National Park.
” data-image-caption=”David Gordon backpacking the Teton Crest Trail in Grand Teton National Park. Click photo to get my customized help planning your trip.
” data-medium-file=”https://i0.wp.com/tbo-media.sfo2.digitaloceanspaces.com/wp-content/uploads/2019/09/06232029/DSC_2658.jpg?fit=300%2C175&ssl=1″ data-large-file=”https://i0.wp.com/tbo-media.sfo2.digitaloceanspaces.com/wp-content/uploads/2019/09/06232029/DSC_2658.jpg?fit=900%2C525&ssl=1″ src=”https://i0.wp.com/tbo-media.sfo2.digitaloceanspaces
Did you miss our previous article…
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New Simulation Explains how Supermassive Black Holes Grew so Quickly

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One of the main scientific objectives of next-generation observatories (like the James Webb Space Telescope) has been to observe the first galaxies in the Universe – those that existed at Cosmic Dawn. This period is when the first stars, galaxies, and black holes in our Universe formed, roughly 50 million to 1 billion years after the Big Bang. By examining how these galaxies formed and evolved during the earliest cosmological periods, astronomers will have a complete picture of how the Universe has changed with time.

As addressed in previous articles, the results of Webb‘s most distant observations have turned up a few surprises. In addition to revealing that galaxies formed rapidly in the early Universe, astronomers also noticed these galaxies had particularly massive supermassive black holes (SMBH) at their centers. This was particularly confounding since, according to conventional models, these galaxies and black holes didn’t have enough time to form. In a recent study, a team led by Penn State astronomers has developed a model that could explain how SMBHs grew so quickly in the early Universe.

The research team was led by W. Niel Brandt, the Eberly Family Chair Professor of Astronomy and Astrophysics at Penn State’s Eberly College of Science. Their research is described in two papers presented at the 244th meeting of the American Astronomical Society (AAS224), which took place from June 9th to June 13th in Madison, Wisconsin. Their first paper, “Mapping the Growth of Supermassive Black Holes as a Function of Galaxy Stellar Mass and Redshift,” appeared on March 29th in The Astrophysical Journal, while the second is pending publication. Fan Zou, an Eberly College graduate student, was the lead author of both papers.

Illustration of an active quasar. What role does its dark matter halo play in activating the quasar? Credit: ESO/M. Kornmesser
Illustration of an active quasar. New research shows that SMBHs eat rapidly enough to trigger them. Credit: ESO/M. Kornmesser

As they note in their papers, SMBHs grow through two main channels: by accreting cold gas from their host galaxy or merging with the SMBHs of other galaxies. When it comes to accretion, previous research has shown that a black hole’s accretion rate (BHAR) is strongly linked to its galaxy’s stellar mass and the redshift of its general stellar population. “Supermassive black holes in galaxy centers have millions-to-billions of times the mass of the Sun,” explained Zhou in a recent NASA press release. How do they become such monsters? This is a question that astronomers have been studying for decades, but it has been difficult to track all the ways black holes can grow reliably.”

For their research, the team relied on forefront X-ray sky survey data obtained by NASA’s Chandra X-ray Observatory, the ESA’s X-ray Multi-Mirror Mission-Newton (XMM-Newton), and the Max Planck Institute for Extraterrestrial Physics’ eROSITA telescope. They measured the accretion-driven growth in a sample of 8000 active galactic nuclei (AGNs) located in 1.3 million galaxies. This was combined with IllustrisTNG, a suite of state-of-the-art cosmological simulations that model galaxy formation, evolution, and mergers from Cosmic Dawn to the present. This combined approach has provided the best modeling to date of SMBH growth over the past 12 billion years. Said Brandt:

“During the process of consuming gas from their hosting galaxies, black holes radiate strong X-rays, and this is the key to tracking their growth by accretion. We measured the accretion-driven growth using X-ray sky survey data accumulated over more than 20 years from three of the most powerful X-ray facilities ever launched into space.

“In our hybrid approach, we combine the observed growth by accretion with the simulated growth through mergers to reproduce the growth history of supermassive black holes. With this new approach, we believe we have produced the most realistic picture of the growth of supermassive black holes up to the present day.”

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This still image shows the timeline running from the Big
Did you miss our previous article…
https://mansbrand.com/10-tips-for-taking-kids-on-their-first-backpacking-trip-3/

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