Posts tagged star
CU-Boulder study: Spiral galaxies like Milky Way bigger than thought
Jun 27th
CU-Boulder Professor John Stocke, study leader, said new observations with Hubble’s $70 million Cosmic Origins Spectrograph, or COS, designed by CU-Boulder show that normal spiral galaxies are surrounded by halos of gas that can extend to over 1 million light-years in diameter. The current estimated diameter of the Milky Way, for example, is about 100,000 light-years. One light-year is roughly 6 trillion miles.
The material for galaxy halos detected by the CU-Boulder team originally was ejected from galaxies by exploding stars known as supernovae, a product of the star formation process, said Stocke of CU-Boulder’s astrophysical and planetary sciences department. “This gas is stored and then recycled through an extended galaxy halo, falling back onto the galaxies to reinvigorate a new generation of star formation,” he said. “In many ways this is the ‘missing link’ in galaxy evolution that we need to understand in detail in order to have a complete picture of the process.”
Stocke gave a presentation on the research June 27 at the University of Edinburgh’s Higgs Centre for Theoretical Physics in Scotland at a conference titled “Intergalactic Interactions.” The CU-Boulder research team also included professors Michael Shull and James Green and research associates Brian Keeney, Charles Danforth, David Syphers and Cynthia Froning, as well as University of Wisconsin-Madison Professor Blair Savage.
Building on earlier studies identifying oxygen-rich gas clouds around spiral galaxies by scientists at the Space Telescope Science Institute in Baltimore, the University of Massachusetts, Amherst College and the University of California, Santa Cruz, Stocke and his colleagues determined that such clouds contain almost as much mass as all the stars in their respective galaxies. “This was a big surprise,” said Stocke. “The new findings have significant consequences for how spiral galaxies change over time.”
In addition, the CU-Boulder team discovered giant reservoirs of gas estimated to be millions of degrees Fahrenheit that were enshrouding the spiral galaxies and halos under study. The halos of the spiral galaxies were relatively cool by comparison — just tens of thousands of degrees — said Stocke, also a member of CU-Boulder’s Center for Astrophysics and Space Astronomy, or CASA.
Shull, a professor in CU-Boulder’s astrophysical and planetary sciences department and a member of CASA, emphasized that the study of such “circumgalactic” gas is in its infancy. “But given the expected lifetime of COS on Hubble, perhaps another five years, it should be possible to confirm these early detections, elaborate on the results and scan other spiral galaxies in the universe,” he said.
Prior to the installation of COS on Hubble during NASA’s final servicing mission in May 2009, theoretical studies showed that spiral galaxies should possess about five times more gas than was being detected by astronomers. The new observations with the extremely sensitive COS are now much more in line with the theories, said Stocke.
The CU-Boulder team used distant quasars — the swirling centers of supermassive black holes — as “flashlights” to track ultraviolet light as it passed through the extended gas haloes of foreground galaxies, said Stocke. The light absorbed by the gas was broken down by the spectrograph, much like a prism does, into characteristic color “fingerprints” that revealed temperatures, densities, velocities, distances and chemical compositions of the gas clouds.
“This gas is way too diffuse to allow its detection by direct imaging, so spectroscopy is the way to go,” said Stocke. CU-Boulder’s Green led the design team for COS, which was built by Ball Aerospace & Technologies Corp. of Boulder for NASA.
While astronomers hope the Hubble Space Telescope keeps on chugging for years to come, there will be no more servicing missions. And the James Webb Space Telescope, touted to be Hubble’s successor beginning in late 2018, has no UV light-gathering capabilities, which will prevent astronomers from undertaking studies like those done with COS, said Green.
“Once Hubble ceases to function, we will lose the capability to study galaxy halos for perhaps a full generation of astronomers,” said Stocke. “But for now, we are fortunate to have both Hubble and its Cosmic Origins Spectrograph to help us answer some of the most pressing issues in cosmology.”
The study was supported by a NASA/Hubble Space Telescope contract to the Cosmic Origins Spectrograph science team, general NASA/Hubble Space Telescope observing grants to Stocke and a National Science Foundation grant to Keeney.
-CU-
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Buffs Fall To Wildcats In OT After Controversial Call
Jan 4th
The Buffs believed they had won when senior Sabatino Chen banked in a three-pointer at the final buzzer in regulation of their Pac-12 Conference opener. But after conferring with the timekeepers and watching the replay monitor at McKale Arena, officials disallowed Chen’s shot and the game went into OT.
Shown a replay of Chen’s trey before his postgame interview with KOA Radio, CU coach Tad Boyle said, “That just makes me sick to my stomach . . . I’m sick to my stomach because I think our team deserved to win that game. But we didn’t and we have to move on from it.”
Boyle said he was proud of his team and that it “had that game won in a lot of ways.” He also promised the Buffs would move on, but they also would remember: “We’re not going to move on as, ‘Oh, were going to forget about it and move on.’ We’re going to remember this because you have to remember this feeling. If it doesn’t hurt in the pit of your stomach and you’re not a little bit pissed off then something is wrong with you.”
In the overtime, it was all Wildcats, who trailed by as many as 17 points in the first half and 16 in the second. Less than a minute into overtime, they took their first lead since 5-4 on a three-point play by Kevin Parrom to make it 83-82.
The Buffs tied it at 83-83 on one of two free throws by Xavier Johnson, who made his first career start in place of Chen. But CU didn’t score again. Arizona – beaten twice by CU last season, the final time for the Pac-12 tournament title – got nine more points and rolled to its first 13-0 start since 1931-32.
The Buffs (10-3, 0-1) play at Arizona State on Sunday at 6 p.m.
Five CU players scored in double figures, topped by Askia Booker’s 18. Freshman Josh Scott and Chen scored 15 each – a career-high for Chen – while Johnson had 13 and Spencer Dinwiddie 11.
Arizona’s Mark Lyons, who sent the game into overtime with a pair of free throws with 9.2 seconds left in regulation, led all scorers with 24 points. He made all 10 of his free throw attempts, while CU hit 17-of-29. In the final 1:44 of regulation, holding a seven-point lead, the Buffs made only three of eight free throw attempts.
“You have to look at the free throws,” Boyle said. “We shot 58 percent for the game; we got away with that earlier in the year at times but tonight we didn’t get away with it, it cost us the game. And I’m not talking any one guy, I’m talking about as a team. So, you’ve got to look at what you can do better, and that is what we can do.”
CU committed only 11 turnovers, but four of them came in the final 2 minutes when Arizona was catching up. Counting the 5 extra minutes, the Wildcats outscored the Buffs 22-5 in the final 6:44. Boyle said he thought his team “got a little soft defensively at the end. Second half they shot 60 percent from the field and we’re one stop away from that game, we’re one or two free throws away from that game . . .
“I asked our guys to play hard, play smart, and to play together. I thought we played hard, I thought we played together, I thought at times we didn’t play smart and those are the things we have to learn as a young team on the road in an environment like this.”
The Buffs, who led by 10 points with 1:53 remaining in regulation, played the extra period minus Andre Roberson. He fouled out in the final 2 minutes of regulation with nine points and 11 rebounds.
For the first time since the opening game, Boyle changed his starting lineup, inserting the 6-6 freshmen Johnson in the place of the 6-4 senior Chen. And Boyle’s move paid immediate dividends as the Buffs started fast by slowing it down. CU controlled the pace and led by as many as 17 points (30-13) with 4:30 remaining in the first half.
CU pulled away with a 15-1 run, and “XJ” was instrumental in that spurt. After opening the scoring with a layup, he finished the half with 12 points, including a pair of the Buffs’ six three-pointers that tied their season high. They finished 10-of-21 from beyond the arc.
But CU was certain that Arizona would snap to life, and it happened in the half’s final 4:30. After their long drought (three field goals) in the opening 15 minutes, the Wildcats closed the half on a 14-4 run and trailed by only 7 (34-27) at intermission.
Helping Johnson with CU’s first-half scoring load was Booker, who contributed three of the Buffs’ treys and finished the half with 11 points. But a Booker miscue in the final 25 seconds also helped the Wildcats boost their momentum heading into their locker room. At the 3.5 second mark, a Booker turnover and subsequent foul sent Nick Johnson to the foul line.
He hit both free throws with 2.2 seconds showing, cutting the Buffs’ lead to 34-27 and finally awakening the McHale Center crowd. But Arizona’s total tied for its lowest of the season, and it matched its field goal total with seven turnovers.
The Buffs opened the second half with the same intensity as they did the first, outscoring the Wildcats 7-0 on two free throws by Scott, a three-pointer by Roberson from the right corner on an assist by Booker and a Roberson throw-down in transition on a sweet lob by Dinwiddie.
CU was up again by 14 (43-29), but the Buffs knew they couldn’t rest on that margin. And other factors came into play: About 51/2 minutes in, both teams had to sit a star each. Roberson went to his bench with three fouls and Solomon Hill to his with four fouls.
After Arizona pulled to within 10 (45-35), Chen replaced Roberson and promptly contributed a conventional three-point play, then hit a trey from the left corner as the Buffs went back ahead by 16 (56-40).
The Buffs were expecting a Wildcats run, but they withstood this one. Just shy of the 10-minute mark, Chen delivered another trey to push CU up 59-49, and the Buffs held that 10-point margin until Lyons hit a layup and Hill followed with a three-pointer.
Suddenly, Arizona was within six (64-58) with just over 6 minutes left.
No sweat for Chen. He hit consecutive layups – the second on a goal-tending call – to restore a double-digit CU lead (68-58) with 41/2 to play. The Buffs kept that 10-point advantage (73-63) on a trey by Booker from the left wing with 2:47 left.
Booker hit two free throws at the 1:53 mark for another 10-point CU lead (75-65), but a traditional three-point play by Lyons pulled the Wildcats to within 75-68 with 1:49 remaining.
With 1:33 left, Arizona trimmed CU’s lead to 78-73 on a three-pointer by Hill, then to 78-74 on one of two free throws by Johnson as Roberson committed a turnover and fouled out. The Wildcats caught the Buffs at 80-80 on Lyons’ pair of free throws, setting up Chen’s nullified three-pointer at the buzzer.
And if the replay monitor wasn’t kind to the Buffs, neither was overtime.
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The Christmas Story of the Birth of Jesus
Dec 24th
His power knows no limits. For those who call his name profound miracles have happened even in this day. The following is the story of the first miracle.
The Christmas Story of the Birth of Jesus – Paraphrased from the Bible:
This Christmas story gives a biblical account of the events surrounding the birth of Jesus Christ. The Christmas story is paraphrased from the New Testament books of Matthew and Luke in the Bible.
References:
Matthew 1:18-25; Matthew 2:1-12; Luke 1:26-38; Luke 2:1-20.
The Conception of Jesus Foretold
Mary, a virgin, was living in Galilee of Nazareth and was engaged to be married to Joseph, a Jewish carpenter. An angel visited her and explained to her that she would conceive a son by the power of theHoly Spirit. She would carry and give birth to this child and she would name him Jesus.
At first Mary was afraid and troubled by the angel’s words. Being a virgin, Mary questioned the angel, “How will this be?” The angel explained that the child would be God’s own Son and, therefore, “nothing is impossible with God.” Humbled and in awe, Mary believed the angel of the Lord and rejoiced in God her Savior.
Surely Mary reflected with wonder on the words found in Isaiah 7:14 foretelling this event, “Therefore the Lord himself will give you a sign: The virgin will be with child and will give birth to a son, and will call him Immanuel.” (NIV)
The Birth of Jesus:
While Mary was still engaged to Joseph, she miraculously became pregnant through the Holy Spirit, as foretold to her by the angel. When Mary told Joseph she was pregnant, he had every right to feel disgraced. He knew the child was not his own, and Mary’s apparent unfaithfulness carried a grave social stigma. Joseph not only had the right to divorce Mary, under Jewish law she could be put to death by stoning.
Although Joseph’s initial reaction was to break the engagement, the appropriate thing for a righteous man to do, he treated Mary with extreme kindness. He did not want to cause her further shame, so he decided to act quietly. But God sent an angel to Joseph in a dream to verify Mary’s story and reassure him that his marriage to her was God’s will. The angel explained that the child within Mary was conceived by the Holy Spirit, that his name would be Jesus and that he was the Messiah, God with us.
When Joseph woke from his dream, he willingly obeyed God and took Mary home to be his wife, in spite of the public humiliation he would face. Perhaps this noble quality is one of the reasons God chose him to be the Messiah’s earthly father.
Joseph too must have wondered in awe as he remembered the words found in Isaiah 7:14, “Therefore the Lord himself will give you a sign: The virgin will be with child and will give birth to a son, and will call him Immanuel.” (NIV)
At that time, Caesar Augustus decreed that a census be taken, and every person in the entire Roman world had to go to his own town to register. Joseph, being of the line of David, was required to go to Bethlehem to register with Mary. While in Bethlehem, Mary gave birth to Jesus. Probably due to the census, the inn was too crowded, and Mary gave birth in a crude stable. She wrapped the baby in cloths and placed him in a manger.
The Shepherd’s Worship the Savior:
Out in the fields, an angel of the Lord appeared to the shepherds who were tending their flocks of sheep by night. The angel announced that the Savior had been born in the town of David. Suddenly a great host of heavenly beings appeared with the angels and began singing praises to God. As the angelic beings departed, the shepherds decided to travel to Bethlehem and see the Christ-child.
There they found Mary, Joseph and the baby, in the stable. After their visit, they began to spread the word about this amazing child and everything the angel had said about him. They went on their way still praising and glorifying God. But Mary kept quiet, treasuring their words and pondering them in her heart. It must have been beyond her ability to grasp, that sleeping in her arms—the tender child she had just borne—was the Savior of the world.
The Magi Bring Gifts:
After Jesus’ birth, Herod was king of Judea. At this time wise men (Magi) from the east saw a star, they came in search, knowing the star signified the birth of the king of the Jews. The wise men came to the Jewish rulers in Jerusalem and asked where the Christ was to be born. The rulers explained, “In Bethlehem in Judea,” referring to Micah 5:2. Herod secretly met with the Magi and asked them to report back after they had found the child. Herod told the Magi that he too wanted to go and worship the babe. But secretly Herod was plotting to kill the child.So the wise men continued to follow the star in search of the new born king and found Jesus with his mother in Bethlehem. (Most likely Jesus was already two years of age by this time.) They bowed and worshiped him, offering treasures of gold, incense, and myrrh. When they left, they did not return to Herod. They had been warned in a dream of his plot to destroy the child.
By Mary Fairchild, About.com Guide