นักดาราศาสตร์​ MIT ค้นพบกระจุกกาแล็คซี่ใหม่ ที่คนอื่นหาพลาดไป

เขียนโดย Kelso Harper 

วันที่ 26 มีนาคม 2021

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นักดาราศาสตร์​จาก MIT ได้ค้นพบกระจุกกาแล็คซี่ใหม่ที่มีความพิเศษแตกต่างไปจากกาแล็กซี่เดิมๆ ในงานวิจัยที่มีในปัจจุบัน ผลการศึกษาที่ได้ตีพิมพ์วันนี้ เสนอว่าประมาณ 1 เปอร์เซ็นต์ของกระจุกกาแล็คซี่ มีความพิเศษ  ทำให้ถูกจำแนกผิดเป็นแค่หนึ่งกาแล็คซี่ที่สว่างเฉยๆ ได้ เมื่อนักวิทยาศาสตร์สร้างกล้องโทรทัศน์ใหม่ขึ้น ก็ควรที่จะใส่ใจกับรายละเอียดผลการศึกษานี้ ไม่เช่นนั้นก็อาจจะมีความเข้าใจจักรวาลได้แบบไม่ครบสมบูรณ์

Journey to the Total Solar Eclipse 2017

The planning for this trip is very different from any other trips as it was the first time that the focus of the trip is one particular event at a particular time and nothing else. The trip was formed rather quickly as I found one of my physics friend who is also interested in going to see the solar eclipse. We looked up the map and decided where in this solar eclipse path that we can potential go with rather cheap flight tickets and no driving involved. After few hours, we decided that we will fly to Atlanta and will take a bus to a nearby (4 hours drive) town, called Columbia, SC without knowing anything about the town or anyone there. I later learned once I got to the city that it is actually the capitol city of South Carolina. You would not have guess that if you did not visit the state museum there. 

We flew Spirit to Atlanta on Saturday afternoon before catching a late evening bus to Columbia. We had to wait for the bus in the middle of the night for an hour. I thought that the station should be indoor with restrooms and restaurants. I was completely wrong. We in fact had to wait on the sidewalk. The bus took about 4 hours to get to Columbia and 3 AM. I was tired (from traveling and probably jetlag from my previous trip). We managed to get to the hotel with a plan that we will visit the state museum the next day for the eclipse glasses. 

SC State Museum with the telescope dome at the top pointing to the sun

Wind is what we have to worry about

From the previous post, we were talking about observational astronomy. Specifically, we talked about 'seeing' and how weather can affect the ability for the astronomers to do observation. In this post, I want to talk specifically about wind.

You might be wondering how is wind has an effect on the telescope. The answer is a strong wind can  literally shake the telescope and have a damage on the telescope itself. The criterion for a strong wind is 35 mph (56 km/h). Therefore, every time the wind gets stronger, a telescope operator (a person who is responsible for moving the telescope and dome) will shut down the dome to protect the telescope from the wind and an astronomer can just sit there waiting for the wind to stop. If you think sitting and waiting for cloud to go away is bad, waiting for the wind to stop is even worse simple because you can literally see a clear night sky outside your dome, but you simply cannot do the observation.

A wind chart from 3/17-6/17

Average Seeing on Magellan Telescope in the past 4 months

It has been awhile since I wrote my last blog post. I am not sure why. Maybe I felt like 'blogging' was no longer exciting and novel, or maybe I just spent too much time consuming media and did not create anything. Then, someone commented on one of my old data visualization works that I did several years ago about Bangkok. Thank you to that person since it made me want to write a new one again.

Enough about excuses. Today, we will discuss about something that is near and dear to my heart, which is observational astronomy. During my PhD study, I got a chance to visit Magellan Telescope in northern part of Chile (I mentioned a little bit at the end of my last post). However, coming to the telescope is not enough for this kind of works. Weather also plays a huge role in this kind of works. And as we all know, we cannot really control weather. More often than not, astronomers travel to the top of the mountains, sit quietly inside the dome, and wait for the cloud to disappear. But, how often? 

To answer this question, we have to pick a specific place and time to get a finite answer. Naturally, I picked Magellan Telescope and within the last 4 months as a starting point. I put the method and all the resources that I used in the note below.

Seeing at Magellan Telescope from 3/17-6/17

What I learn from Astrostatistics Summer School at Penn State

During my first summer as a graduate student at MIT, I got an opportunity to participate in the 12th Astrostatistics Summer School at Pennsylvania State University (Penn State), organized by Eric Feigelson in the Department of Astronomy and Astrophysics. My first impression about the summer school is mostly about some fancy statistical techniques that astronomers are adopting in their research to do data analysis. But the reality is much more than I can ever imagine.

Learn Bayesian Statistics from Thomas Loredo

The Second Part of AAS 227th Meeting in Florida: Poster!

While the first post for AAS meeting is about my experience at the conference in general, the second post will be dedicated mostly on my first experience in a poster presentation.

During mid-October, my advisor and I decided that I should give a poster presentation on my current research project at AAS as a good way to introduce my project to the community in order to gather feedbacks about it. I spent around two weeks in December working with the poster from creating a template for the poster, generating the information, figures and diagram, and finalizing the poster. It was a rewarding experience as you got to see the physical poster at the end. We decided to use a fabric poster for easy packing and traveling which made an awesome poster.

My first poster for the AAS Meeting

AAS 227th Meetng in Orlando, Florida

I would say that I am fairly lucky to have a chance to join this year AAS meeting because not many first-year graduate students usually come to the meeting. My main goals for this meeting are attending my first "Astropy" workshop and presenting the progress of my current research project about finding galaxy clusters. The size and the scale of this meeting are completely different from my first scientific meeting I attended last year in Vietnam. There are more than ten sessions running at the same time covered not only all kinds of research topics in astrophysics from exoplanet to cosmology, but also public outreach and other astrophysics-related topics such as coding and writing papers. The conference could easily feel overwhelming as many events occur simultaneously. I can only write about the conference from my own perspective, and keep in mind that each one of us will have a totally different experience.

AAS 227th Meeting at Kissimmee, Florida

UTRIP: How I spent my last summer of college

During the summer of 2014, I had a chance to participate in University of Tokyo Research Internship Program (UTRIP) with the financial support from Friends of UTokyo, Inc. UTRIP is an undergraduate summer research internship program with top professors for those who want to pursuing Ph.D. degree in science in the future.

Prof.Tamura's seminar on the topic of Exoplanets

I participated in the Exoplanet Lab in the Astronomy Department hosted by Prof. Motohide Tamura. The main focus of the lab is about direct imaging technique to observe several types of objects such as exoplanets and protoplanetary disks. The data mostly comes from Subaru Telescope which is the 8.2 meter telescope of the National Astronomical Observatory of Japan (NAOJ), located at Mauna Kea Observatory in Hawaii. My research background is astrophysics, mainly exoplanet using transiting technique. Thus, I was really excited once I knew that I would learn this new technique, direct Imaging, to detect planets. Direct imaging planets are extraordinary because we can actually see a planet itself instead of an indirectly observed planet from technique such as transiting and radial velocity. By being able to see a planet, we can confidently say that we found an extrasolar planet and a planet does exist outside our solar system.

Comment on Primordial Gravitational Waves by Prof. Daniel Holz

Primordial gravitational waves may have been detected in this swirly pattern of light from the early universe. Image: BICEP2 Collaboration

I took a class called Spacetime and Black Holes during the fall quarter of my third year and the professor for that class was Prof. Daniel Holz. Some of his work also relates to gravitational wave and general relativity. After the announcement of the discovery, he gave us a comment about this latest and most excited finding so far this year about the first direct detection of gravitational waves and how it becomes an evidence for the inflation theory of the early universe. I thought I would like to share this here since we are all in a moment of history where most physics might start to change from this point on.

Ryerson Astronomical Society (RAS) in 1950s

As a science major student, I always learned about history of science, specifically physics and astrophysics. For example, Galileo created the first telescope, or Newton invented Newton's three laws of motion, then Einstein found Relativity that contradicted with almost everything Newton said. "Why do we have to learn Newton's three laws then?" I often asked myself why they have to teach about the history of science since it will never help me solve Schrödinger equation equations or any physics equations.

It is not until I learned that these discoveries did not happen far away from where my classes are that I realized how amazing it felt to be a part of the big community of science. Milikan's oil drop experiment occurred in the basement of where I took my first-year Calculus, or Enrico Fermi engineered the first controlled, self-sustaining nuclear chain reaction happened at the library where I often cramped my final exam studies until the last minute. 

Prof. Vandervoort gave a talk on the history of RAS on 1/27/2014

Pale Blue Dot: A Vision of the Human Future in Space - Carl Saga

The Pale Blue Dot is a photograph of planet Earth taken in 1990 by the Voyager 1 spaceprobe from a record distance of about 6 billion kilometers (3.7 billion miles) from Earth.

From this distant vantage point, the Earth might not seem of any particular interest. But for us, it's different. Consider again that dot. That's here. That's home. That's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every "superstar," every "supreme leader," every saint and sinner in the history of our species lived there – on a mote of dust suspended in a sunbeam. 

Yerkes Observatory

Yerkes Observatory: University of Chicago's Observatory in Wisconsin

Here is the Yerkes Observatory owned by University of Chicago even though it is roughly two-hours drive from the university. Yerkes is a home of the world biggest refracting telescope. 

I just feel like I should visit more observatories, not just because I want to travel to many different places, but also because they always remind me of what my dream was like when I was a kid. About 15s in front of the observatory that night was amazing. The sky is clear, but I could not remember anymore what are these constellations. The actually telescopes are located in both side of this building with this in the middle.