CLASSIFYING THE ENVIRONMENT OF HI-RICH EARLY-TYPE GALAXIES USING - - PowerPoint PPT Presentation
CLASSIFYING THE ENVIRONMENT OF HI-RICH EARLY-TYPE GALAXIES USING PYTHON Advisor: Mary Crone Odekon, Professor and Chair, Physics Department Kelly Cantwell, 2018 Erin Maloney, 2018 Henry Thoreen, 2018 http://naturalhistory.si.
Advisor: Mary Crone Odekon, Professor and Chair, Physics Department Kelly Cantwell, 2018 Erin Maloney, 2018 Henry Thoreen, 2018
http://naturalhistory.si. edu/exhibits/evolving- universe/full/Gcen3col. jpg
https://www.reddit. com/r/DotA2/comments/3545t2/f un_little_facts_about_the_new_b lack_hole/
★ Two type of galaxies: ○ Early-Type Galaxies (ETG) ○ Late-Type Galaxies (LTG) ★ Early-Type Galaxies typically have elliptical morphology and little to no new stars forming ○ ETG refers to older galaxies, with stars that formed earlier in the history of the universe ○ More red in color, less bright ★ Late-Type Galaxies typically have spiral morphology and lots of new star formation ○ LTG refers to younger galaxies, with stars that are still forming in the late era of the universe ○ More blue in color, very bright
http://www.wolaver.
http://i1.wp.com/www. universetoday.com/wp- content/uploads/2013/10/milky_wa y.jpg?resize=350%2C200
★ How to locate things on the sky: ○ Right Ascension (east vs west) ○ Declination (north vs south) ○ Red Shift (radially out) ★ Right Ascension (RA): ○ How far to the right of the Prime Meridian ○ Measured in hours, minutes and seconds ★ Declination (Dec): ○ Angular distance (north/south) from the celestial equator ○ Measured in degrees ★ Red Shift ○ The shift of light waves towards longer wavelengths or “red-er” wavelengths ○ Used in astronomy as a radially outward distance measure, measured in km/s/Mpc
http://www.uwgb. edu/dutchs/Graphics- Geol/Astronomy/RA- Dec.gif
★ HI Gas ○ Neutral Atomic Hydrogen Gas ★ What does it usually mean? ○ Indicates new star formation ○ Often found in LTGs ★ How do we detect it? ○ Emits 21 cm wavelength (1420.4 MHz) - radio waves! ■ Transition between atomic spin ½ states while in the ground (1s) state ○ Use radio telescopes to detect it -- Arecibo and Green Bank ★ Why do WE look at it? ○ Some ETGs have HI gas, this is abnormal ○ Trying to figure out WHY the HI is present in these ETGs
http://hyperphysics. phy-astr.gsu. edu/hbase/quantum/im gqua/h21.gif
http://www.spaceanswers.com/deep-space/this-is-what-two-colliding-galaxies-look-like/
★ Existing Python codes needed to be debugged before they could output necessary calculations ★ Step one: learn Python 2.7! ★ http://www.learnpythonthehardway.org/ ★ (no, not this type of python)
http://kaijutegu.tumblr. com/post/134642306048/umblyun- kaijutegu-umblyun-submitted-im
★ 3 Programs that we worked on:
○ 2 needed modification
■ Nearest Neighbor Density ■ Large-Scale Environment
○ 1 new
■ Galaxy Matching
http://www.answers. com/article/523004/unlock-the- code-what-the-computer-codes-for- cars-really-mean
★ Helps classify the local environment of each galaxy ★ Needed debugging ★ Calculates the 3rd neighbor density for each galaxy
○ Divides the area of a circle with radius of the distance to the third closest galaxy by 3
★ Calculates the average density
○ Calculates then sums the densities for the second through the tenth closest galaxies, then divides by 9
★ Calculates the 3rd to average ratio
○ Shows the uniformity (or lack thereof) of the local density of each galaxy
https://www.youtube.com/watch? v=NESNKdybWGk
★ Classifies the large scale environment of each galaxy into groups, filaments, tendrils, and voids
○ Uses the graph method of Minimal Spanning Trees to find the filaments and tendrils using the groups as nodes
★ Needed modification
○ Input and implementation too complex for practical use
★ Matches known galaxies detected optically with those in our catalog (detected in HI) ★ Calculates the projected distance from the HI detection to the nearest known galaxy and assigns the density values of that galaxy to the HI galaxy detection ★ Considers only galaxies with a recessional velocity difference of less than 1000 km/s
○ Here recessional velocity is c*Z, or speed of light times the redshift ○ (can be thought of as the 3rd dimension for a 3D distance calculation)
★ Jones, Michael G.; Papastergis, Emmanouil; Haynes, Martha P.; Giovanelli, Riccardo, 2016, MNRAS, 457, 4393 ★ Shaw, Zed; Learn Python the Hard Way 3rd Edition; http://learnpythonthehardway.
★ Barrow, John D. et al, 1985: Minimal Spanning Trees, Filaments, and Galaxy Clustering ★ Alpaslan, Mehemen et al, 2013: Galaxy and Mass Assembly (GAMA): The large scale structure of galaxies and comparison to mock universities
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http://www.deviantart. com/art/Quasar- 211879065
Skidmore College Student/Faculty Collaborative Research grant Sloan Digital Sky Survey DR7 Schupf Scholars program National Science Foundation AST Award 1211005 Arecibo and Green Bank
http://www.australianscience.com. au/wp-content/uploads/2012/03/Earth- from-the-Moon-photo-credit-NASA.jpg
https://www.youtube.com/watch?v=ykWPyaqbebo
Crab Nebula