Astro 322 Winter 2011 Feb. 7

Monday, February 7, 2011 normal spirals

irregu ellipticals lars

lenticulars barred spirals “tuning-fork” diagram

Monday, February 7, 2011 Monday, February 7, 2011 Galaxies classification: key differences: total mass, gas/ ratio, mass-to-light ratio

gas/stars ratio is connected with:

•flatness of •current SFR •ages of stellar population, colors of stars •spiral structure

Monday, February 7, 2011 Surface brightness, isophote, profile

15 Night sky at 22.7 20 µB 25

30 radius

µB

R1/4 Vaucouleurs law

Monday, February 7, 2011 elliptical galaxies sequence: oblate/prolate classification based on ratio 10 (1-b/a) of galaxy’s isophotes

M32 E2 M87 E0p NGC 4660, E7

7 13 10 - 10 Msun M110 E6

Monday, February 7, 2011 elliptical galaxies sequence: oblate/prolate classification based on ratio 10 (1-b/a) of galaxy’s isophotes

M32 E2 M87 E0p NGC 4660, E7

7 13 10 - 10 Msun M110 E6

Monday, February 7, 2011 elliptical galaxies sequence: oblate/prolate classification based on ratio 10 (1-b/a) of galaxy’s isophotes

M32 E2 M87 E0p NGC 4660, E7

7 13 10 - 10 Msun M110 E6

Monday, February 7, 2011 lenticular galaxies: some dust/gas, no spiral arms NGC 2787 SB0

Spindle galaxy, S0

NGC 4526, SB0 Monday, February 7, 2011 lenticular galaxies: some dust/gas, no spiral arms

Cartwheel galaxy (S pec ring)

Monday, February 7, 2011 Supergiant ellipticals/lenticular: centrally dominant (cD) more diffuse, larger haloes, more akin to lenticular IC 1101 Galaxy: NGC 1275: cD galaxy + high velocity system diameter 1700 kpc,1014 stars origin of cold filaments is unknown

Monday, February 7, 2011 dwarf ellipticals (dE) sometimes mentioned to be intermediate between GC and E not fully correct: dark matter

M32 Andromeda (M31)

M110

Monday, February 7, 2011 dwarf ellipticals (dE) sometimes mentioned to be intermediate between GC and E not fully correct: dark matter

M32 Andromeda (M31)

M110

M110 Е5

Monday, February 7, 2011 compact ellipticals: small sizes and high stellar densities

M32

Andromeda (M31)

M110

(By Lanoue)

Monday, February 7, 2011 compact ellipticals: small sizes and high stellar densities a small spiral in the past?

M32 compact elliptical Andromeda (M31)

M110

(By Lanoue)

Monday, February 7, 2011 dwarf spheroids (dSph): lower L than in dE, only sattelites A distinct class by stellar population and profile NGC 147 Sculptor

Different by brightness profile from Vast majority of dE and dSph are E and dE, closer to GC however closer by properties to Irr & late have dark matter type galaxies than to E! Monday, February 7, 2011

Vast majority of dE and dSph are closer by properties to Irr & late type galaxies than to E! Spiral galaxies: unbarred, spiral arm sequence from tightly wound arms to loosely wound arms

M81, Sab (Gendler) M31, Sb M101, Scd

Monday, February 7, 2011 Spiral galaxies: barred vs unbarred. a: small body, more tightly wound arms

M104, Sombrero Sa

NGC 6782 SBa

Monday, February 7, 2011 Spiral galaxies: barred vs unbarred. a: small body, more tightly wound arms

M104, Sombrero Sa

NGC 6782 SBa

Monday, February 7, 2011 Spiral galaxies: a-b

Black eye Sab

the interstellar gas in the outer regions of M64 rotates in the opposite direction from the gas and stars in the inner regions

Monday, February 7, 2011 Spiral galaxies: barred vs unbarred b subtype

M81, Sab

NGC1300, SBbc

Monday, February 7, 2011 Spiral galaxies: barred vs unbarred c: loosely wound arms , Scd

NGC 3319, SBc

Monday, February 7, 2011 Spiral galaxies: barred vs unbarred d: diffuse, broken arms made up of individual stellar clusters and nebulae; very faint central bulge M82, Cigar galaxy, Sd (used to be Irr in the past, near IR showed 2 spiral arms)

NGC 2805, SBd

Monday, February 7, 2011 Spiral galaxies: barred vs unbarred d: diffuse, broken arms made up of individual stellar clusters and nebulae; very faint central bulge M82, Cigar galaxy, Sd (used to be Irr in the past, near IR showed 2 spiral arms)

NGC 2805, SBd

Monday, February 7, 2011 Spiral galaxies: m - Magellanic spirals with one spiral arm

NGC 5398, SBdm

NGC 55, SBm

Monday, February 7, 2011 Spiral galaxies: unbarred with ring in such galaxies usually gas counterrotating with respect to stars

NGC 7742 SA(r)b

Monday, February 7, 2011 Ring galaxies

Hoag’s object

NGC 4650A Polar-ring galaxy

Monday, February 7, 2011 Spiral galaxies: grand design prominent and well-defined spiral arms ~10%

M51 SABbc

Monday, February 7, 2011 Flocculent galaxies: functional opposite of the grand design ~30% patchy, with discontinuous spiral arms

NGC 4414, SAc

the rest of galaxies are multi arm galaxies, ~60%

Monday, February 7, 2011

Monday, February 7, 2011 MIlky Way

SBb/SBc grand design

Monday, February 7, 2011 Irregular galaxies: Irr I (Hubble classification) have some structure subtyped in Sm (if have some spiral structure) or Im

LMC -> SBm

SMC -> Im

Monday, February 7, 2011 Irregular galaxies: Irr I (Hubble classification) have some structure subtyped in Sm (if have some spiral structure) or Im

LMC -> SBm

SMC -> Im

Monday, February 7, 2011 Irregular galaxies: Irr I (Hubble classification) have some structure subtyped in Sm (if have some spiral structure) or Im

LMC -> SBm

SMC -> Im

Monday, February 7, 2011 Irregular galaxies: Irr II (Hubble classification) no any structure

NGC 4485 (Hubble & Chandra) hosts ULXs

Monday, February 7, 2011 Irregular galaxies: dIrr dwarf irregular: very important for overal galaxy evolution. Low Z. Lots of gas.

Saggitarius

Sextans A

Monday, February 7, 2011 Monday, February 7, 2011