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Home , Arp 271

Reminder 1. “Runaway Universe” assignment, with an in-class essay next week 2. Final Exam on 05/09 - Mandatory Presence; no make up - Closed online searches - Open book and open notes 3. Misc? This presentation on deviates from the textbook materials

It is built with the next week’s presentation in mind Hubble’s Classification of (Tuning Fork)

http://en.wikipedia.org/wiki/Galaxy_morphological_classification

MWG is SBb - Hubble Classification is improved upon by de Vaucouleurs We will see some examples of each type

Let’s begin with our galactic neighbors The M51 (M51a) (And companion M51b) Grand-design galaxy

Self-sustaining star forming regions along spiral arm

M51b: Lencular? (SB0) Amorphous? Irregular? Our Big Neighbors: M33 and M31 (Barred Spirals)

http://tehgeektive.com/2012/06/12/what-happens-when-two-galaxies-collide-video/ Our Big Neighbors: M33 and M31 (Barred Spirals)

http://apod.nasa.gov/apod/ap121220.html Triangulum Galaxy (Pinwheel) (M33, NGC 598)

http://apod.nasa.gov/apod/ap080124.html (M31, NGC224) M32, a small elliptical dwarf, is above M110, a spheroidal dwarf, is below http:// annesastronomynews.com/annes-picture-of-the-day- the-andromeda-galaxy/ Andromeda - M31 - Barred Spiral

http://apod.nasa.gov/apod/ap130202.html/ http://apod.nasa.gov/apod/ap120518.html Herschel Space Observatory (better than Spitzer) GALEX Bar can be seen! Hot Blue stars (O and B stars) Warm dust à will have star formation (now quiescent) Shows some ring structure – collision with M32? All about Andromeda

Ø 2.5 Mly away (~0.7 Megaparsec); barred spiral Ø Very comparable to the Galaxy Ø Mass, size (2x), age, luminosity, (major) evoluonary path Ø Many more stars (3x more), greater complexity Ø Less star formaon rate, less supernova rate Ø Halo has greater metallicity Ø Globular clusters with greater age range and variety Ø Formed out of many (smaller, early) proto-galaxies; major merger about 8 billion years ago; connuing cannibalism Ø Noceable warped shape and outer ring(s) (MWG also has a ring) à An acve past! M32 and M110 will eventually fall Ø *Type I and II Populaon observaons were based on Andromeda Ø *We understand Andromeda structure more than we understand MWG? Triangulum Galaxy

Ø 3 Mly away; spiral Ø Gravitaonally bound to Andromeda? Ø Compare to MWG Ø 1/10 Mass, half in size, 1/5 #stars, Ø No bulge? Ø No central supermassive black hole? Ø Powerful central x-ray source – unusual (XMM Newton probe) Ø Younger globular clusters Ø Metal rich Ø Lots of young and hot stars Ø Indicate an acve interacon with Andromeda? Andromeda & Milky Way

http://www.nasa.gov/mission_pages/hubble/science/milky-way-collide.html

(Play the movie!!) http://hubblesite.org/newscenter/archive/releases/2012/20/video/a/ Galactic Dynamics Ø Ring Structure Ø Size ~ Milky Way Galaxy Ex: Cartwheel Galaxy Ø Sculptor Constellaon

Diffuse gas in x-ray

OB stars in 2 galaxies

Dust AG/MWG collision may be constructed via simulation plus observational snapshots of current collisions and mergers

NGC 2207 & IC 2163

Do not be fooled!! http://apod.nasa.gov/apod/ap080420.html NGC 2207 & IC 2163

Hubble-Spitzer Composite http://www.spitzer.caltech.edu/images/1618-ssc2006-11b1-Spitzer-and-Hubble-View- of-NGC-2207-and-IC-2163 Galactic collisions are not unusual

http://apod.nasa.gov/apod/ap090407.html ARP 274 & NGC 5679

()

http://apod.nasa.gov/apod/ap080721.html

ARP 271 – NGC 5426-27

(Virgo) Antennae Galaxy – NGC 4038 -4039

Collision has occurred and in progress

Arms torn apart

http://www.spacetelescope.org/news/heic0812/] http://apod.nasa.gov/apod/ap120812.html Galactic Zoo

http://apod.nasa.gov/apod/ap121108.html

Tadpole

(Draco)(A Hubble Legacy picture)

By the way, what do you see other than tadpole and mice?

http://apod.nasa.gov/apod/ap080224.html

The Mice – NGC 4676

(Hubble ACS) (Coma Berenices) Galactic Zoo

http://apod.nasa.gov/apod/ap121108.html

Tadpole

(Draco)(A Hubble Legacy picture)

By the way, what do you see other than tadpole and mice?

http://apod.nasa.gov/apod/ap080224.html

The Mice – NGC 4676

(Hubble ACS) (Coma Berenices) On the universe scale, gravity is the boss. It compacts massive stars into black holes, and now we see that it brings galaxies onto a path of collision. (It does lot more….)

Galaxy Structure Hierarchy The Milky Way Galaxy Local Group Virgo Super Cluster The MWG is a member of the ”Local Group”, a galaxy cluster, along with the Andromeda Galaxy and also the Triangulum Galaxy as the 3 dominant (spiral) galaxies. MWG and AG are barred, Triangulum is unbarred, and all other members are ellipcals or irregular.

Galaxy à Galaxy Group/Cluster à Super Cluster/Group (à Cosmic Web??) (Note: defined by gravity)

hp://en.wikipedia.org/wiki/Observable_Universe hp://en.wikipedia.org/wiki/Local_Group “Local Group” with Milky Way The Big 3: Andromeda – barred spiral, largest Milky Way – barred spiral, most massive Triangulum – unbarred spiral

Barnard’s

http://www.rpi.edu/dept/phys/Courses/Astronomy/LGlayout.gif NGC 6822 – Barnard’s Galaxy

(Ex) Small irregular galaxy near the MWG. 1/10 the size of MGW (7000 lyrs across) http://www.lowell.edu/LARI_welcome.php http://apod.nasa.gov/apod/ap130208.html

Virgo Super Cluster

A Super Cluster is a collection of Galaxy Groups.

Our Local Group is a part of the Virgo Super Cluster that includes Local Group, M81 Group and the .

Local Group is a poor cluster, and Virgo Cluster is a rich cluster. Virgo Cluster is the dominant cluster of the Virgo Super Cluster

http://en.wikipedia.org/wiki/Virgo_Supercluster Virgo (Galaxy) Cluster ; Rich Cluster

http://apod.nasa.gov/apod/ap110422.html

Other galaxy clusters include Fornax, Hercules and Coma hp://heritage.stsci.edu/2005/09/supplemental.html hp://apod.nasa.gov/apod/ap130111.html

“Large-Scale Structure” A prelude

The textbook and misc videos have alluded to the “Large Scale Structure”, loosely defined by the distributions and pattern of galaxies

Let’s visit a site: http://www.miqel.com/space_photos_maps/galactic_info/position-of-milky-way-in- virgo-supercluster.html

Galaxy Surveys Sloan Digital Sky Survey (SDSS) Ex:SDSS, 2dGMAss Galaxy distribution is not random We see an even larger structure In fact the “large scale structure” is

SDSS – 1998 http://apod.nasa.gov/apod/ap980617.html Apache Point Observatory – New Mexico Large Scale structure is inmately ed to “Dark Maer” (and other very interesng astronomical)

Astronomical Zoo Ex

Lensing “Einstein’s Rings” Hubble WFC 3

http://apod.nasa.gov/apod/ap111221.html

CDM & Structure simulation

Lensing “Einstein’s Rings” Hubble WFC 3

http://cosmicweb.uchicago.edu/filaments.html