galaxies and supermassive black holes - … and supermassive black holes josh webster 4/21/2014...

Galaxies and Supermassive Black Holes

Josh Webster

4/21/2014

4/21/2014 Josh Webster 1

http://www.nasa.gov/images/content/690958main_p1237a1.jpg

A Look Ahead


A Look Ahead

• Galaxy Classification

– Hubble Sequence

– De Vaucoulers System


A Look Ahead

• Galaxy Classification

– Hubble Sequence


• Examples of Galaxy Types


A Look Ahead

• Galaxy Classification – Hubble Sequence


• Examples of Galaxy Types

• Active Galactic Nuclei – Supermassive Black Holes

– The center of the Milky Way • Gas cloud approaches SGR A*


Galaxy Classification

The Hubble Sequence (1936)

http://www.astro.caltech.edu/~george/ay21/eaa/eaa-classif.pdf



• E – featureless ovals, ranging from circular

to flattened






to flattened • S0 – lenticular galaxies

w/o spiral structure







w/o spiral structure • S[a-c]- tight spiral

structure, bright central bulge







w/o spiral structure • S[a-c]- tight spiral

structure, bright central bulge

• SB[a-c] – same as S[a-c], but has central bar




Galaxy Classification Continued… The De Vaucoulers System (1959)



• 4 Main Types: • Ellipticals: E • Lenticulars: S0 • Spirals: S • Irregulars: I




• 4 main stages:

• From early to late (a, b, c, d) • Can also be intermediate (ab, bc, cd) • Lenticulars (S0-, S00, S0+) • E+ for late E transitioning to S0




• 4 main stages:


• Irregulars

• Usually denoted “Im” • Magellanic (m) • Transition or spiral type (Sm) • Non-magellanic w/ structure related to S0

(I0)




• 4 main stages:


• Irregulars


(I0)

• Spirals and lenticulars have 2 families: • True nonbarred (SA, SA0) • True barred (SB, SB0) • Intermediate barred (SAB, SAB0)




• 4 main stages:


• Irregulars


(I0)

• Spirals and lenticulars have 2 families: • True nonbarred (SA, SA0) • True barred (SB, SB0) • Intermediate barred (SAB, SAB0)

• Spirals and lenticulars have 2 varieties:

• Ringed (r) • Pure spiral (s) • Transition (rs) • Complete outer ring structure (R) • Psuedo-ring from spiral arms, such as

in S(s) type, (R’)


Rings



An Example of Spiral Varieties



True Nonbarred (SA)

Intermediate (SAB)

True Barred (SB)

True Spiral Transition Ringed

Galaxy Classification Continued…


http://upload.wikimedia.org/wikipedia/commons/8/85/Galaxy_morphology.jpg

A Closer Look at Galaxies


http://apod.nasa.gov/apod/image/1005/m87jet_block.jpg

Elliptical Galaxies

M87



Elliptical Galaxies

M87

Galaxy type: E1 pec • E1: elliptical • Pec: peculiar


http://www.nasa.gov/sites/default/files/potw1329a.jpg

Lenticular Galaxies

NGC 524


http://www.nasa.gov/sites/default/files/potw1329a.jpg

Lenticular Galaxies

NGC 524

Galaxy Type: S0 D • S0: lenticular type • D: rotationally

symmetric w/o pronounced spiral


Spiral Galaxies

http://apod.nasa.gov/apod/image/1006/M51_peris.jpg

M51

NGC 5195


Spiral Galaxies


M51

NGC 5195

Galaxy Type: SA(s)bc pec • SA: spiral w/o bars • (s): w/o rings • bc: intermediate stage • Pec: peculiar


Spiral Galaxies


M51

NGC 5195

Galaxy Type: SA(s)bc pec • SA: spiral w/o bars • (s): w/o rings • bc: intermediate stage • Pec: peculiar

HII region


Barred Spiral Galaxies

NGC 1300

http://upload.wikimedia.org/wikipedia/commons/5/52/Hubble2005-01-barred-spiral-galaxy-NGC1300.jpg 4/21/2014 Josh Webster 33

Barred Spiral Galaxies

NGC 1300

http://upload.wikimedia.org/wikipedia/commons/5/52/Hubble2005-01-barred-spiral-galaxy-NGC1300.jpg

Galaxy Type: SB(rs)bc • SB: barred spiral • (rs): transition • bc: intermediate stage


Irregular Galaxies

NGC 4449

http://apod.nasa.gov/apod/image/1102/NGC4449_hlaGendlerL.jpg 4/21/2014 Josh Webster 35

Irregular Galaxies

NGC 4449

http://apod.nasa.gov/apod/image/1102/NGC4449_hlaGendlerL.jpg

Galaxy Type: IBm I: Irregular B: Barred m: magellanic


What’s at the center of a galaxy?


What’s at the center of a galaxy?


From what we observe, it appears nearly every galaxy contains a supermassive black hole at its center, and it can be “active” or “inactive”.

Active Galactic Nuclei (AGN)



• An active core of a galaxy

– Emits radiation




– Emits radiation

• Very high luminosity over a large range of EM spectrum, based on type.




– Emits radiation

• Very high luminosity over a large range of EM spectrum, based on type.

• Radiation believed to be originating from supermassive black hole at center accreting mass.


Galactic Nuclei Types

http://en.wikipedia.org/wiki/Active_galactic_nucleus#Summary



Supermassive Black Holes

M87



http://hubblesite.org/newscenter/archive/releases/2000/20/image/a/ 4/21/2014 Josh Webster 45


Jet of emitted sub-atomic particles from a source of mass 2 billion times that of the sun.

http://hubblesite.org/newscenter/archive/releases/2000/20/image/a/ 4/21/2014 Josh Webster 45

Center of the Milky Way


http://upload.wikimedia.org/wikipedia/commons/4/43/ESO-VLT-Laser-phot-33a-07.jpg

Center of the Milky Way


https://www.e-education.psu.edu/astro801/content/l8_p7.html

Chandra X-Ray Observatory SGR A* using VLA (radio)

Center of the Milky Way: SGR A*

http://en.wikipedia.org/wiki/File:Pointing_X-ray_Eyes_at_our_Resident_Supermassive_Black_Hole.jpg 4/21/2014 Josh Webster 51

2 d

ay p

eri

od

T

≈ 1

08 K

NuSTAR


Black hole at the center:


2 d

ay p

eri

od

T

≈ 1

08 K

NuSTAR


Black hole at the center: • 4 million times the

mass of the sun


2 d

ay p

eri

od

T

≈ 1

08 K

NuSTAR



mass of the sun • 26,000 Ly from Earth


2 d

ay p

eri

od

T

≈ 1

08 K

NuSTAR



mass of the sun • 26,000 Ly from Earth • Faint X-ray emission


2 d

ay p

eri

od

T

≈ 1

08 K

NuSTAR



mass of the sun • 26,000 Ly from Earth • Faint X-ray emission • Only 1% of material

in vicinity reaches event horizon


2 d

ay p

eri

od

T

≈ 1

08 K

NuSTAR

Stellar Orbits Near SGR A*

http://en.wikipedia.org/wiki/File:Galactic_centre_orbits.svg


S2 orbit ≈ 15.24 years Sedna ≈ 11,400 years S2 velocity ≈ 5000 km/s ≈ 1.67% speed of light That’s 166x Earth’s orbit speed!

Gas Cloud (G2) Near SGR A*

Cloud roughly 10 times the mass of Earth

http://en.wikipedia.org/wiki/File:G2Cloud_eso1151a.jpeg 4/21/2014 Josh Webster 54

Conclusion


Conclusion

• Classifying galaxies and their evolution stages proved to be quite difficult.


Conclusion


• There are many varieties of galaxies. – Their classification can give an idea of what stage of evolution

they are in.


Conclusion



they are in.

• The De Vaucoulers system is an extension of the Hubble sequence, and is the most commonly used.


Conclusion



they are in.

• The De Vaucoulers system is an extension of the Hubble sequence, and is the most commonly used.

• Astrophysics is a rapidly developing field of science. – There is still much that we don’t understand about galaxies. – The technology to observe certain phenomena has only recently

become available. – Everything prior to the early-mid 1900’s was theory or just

speculation.


References

• De Vaucoulers, G. (1962). Revised Classification of 1500 Bright Galaxies. Accessed April 18, 2014 from: http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1963ApJS....8...31D&data_type=PDF_HIGH&whole_paper=YES&type=PRINTER&filetype=.pdf

• Ciardullo, R. (2009). Galaxy Classification. Accessed April 18, 2014 from: http://www2.astro.psu.edu/users/rbc/a504/classifications.pdf

• Torres, Diego F. & Anchordoqui, Luis A. (2004). Astrophysical Origins of Ultrahigh Energy Cosmic Rays. Accessed April 18, 2014 from: http://ned.ipac.caltech.edu/level5/March04/Torres/Torres_contents.html

• NASA & The Hubble Heritage Team (2000). A Cosmic Searchlight. Accessed April 18, 2014 from: http://hubblesite.org/newscenter/archive/releases/2000/20/image/a/

• Boen, Brooke. (2013). Supermassive Black Hole Sagittarius A*. Accessed April 18, 2014 from: http://www.nasa.gov/mission_pages/chandra/multimedia/black-hole-SagittariusA.html

• Murdin, P. & Buta, Ronald (2006). Encyclodpedia of Astronomy and Astrophysics. Accessed April 18, 2014 from: http://www.astro.caltech.edu/~george/ay21/eaa/eaa-classif.pdf


Questions?


galaxies and supermassive black holes - … and supermassive black holes josh webster 4/21/2014...

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