Solo Dwarf Galaxy Survey: Exploring dwarfs in the Local Group Clare - PowerPoint PPT Presentation

Solo Dwarf Galaxy Survey: Exploring dwarfs in the Local Group Clare Higgs PhD Supervisor: Alan McConnachie August 1, 2019 Solo Collaboration: higgs@uvic.ca M. Irwin, N. Annau, N. Bate, G. Lewis, @astrohigglet M. Walker, P . Côté, K. Venn, G. Battaglia

Local Group and a little beyond. Low mass. M V >-18 ➡ Inside 3 Mpc. NEARBY ISOLATED DWARF GALAXIES Not within the virial radius of a large galaxy ➡ More than 300 kpc from M31 and the Milky Way

Why … DWARF GALAXIES ‣ Sensitive probes of galaxy formation and evolution Why … NEARBY ‣ Resolved stellar populations Why … ISOLATED ‣ Intrinsic properties of low mass galaxies Solitary Local (Solo) Dwarf Galaxy Survey

Solo Observations Name Alt. Name RA Dec. Distance E ( B − V ) Tel. Filt. [kpc] [Mags.] 00 h 01 m 58 . 2 s − 15 o 27 0 39” WLM DDO221 933 ± 34 0.030 M gi C gi 00 h 02 m 14 . 5 s +45 o 05 0 20” AndXVIII 1355 ± 81 0.102 C gi 00 h 15 m 31 . 6 s − 32 o 10 0 48” ESO410-G005 KK98 1923 ± 35 0.013 M ugi 00 h 26 m 11 . 0 s − 11 o 02 0 40” Cetus 755 ± 24 0.038 M gi C g 00 h 26 m 33 . 4 s − 41 o 51 0 19” ESO294-G010 2032 ± 37 0.013 M g i 01 h 04 m 47 . 8 s +02 o 07 0 04” IC1613 DDO8 755 ± 42 0.030 M ugi C gi 02 h 24 m 44 . 4 s − 73 o 30 0 51” KKs3 2120 ± 70 0.045 M gi 03 h 01 m 22 . 8 s +40 o 59 0 17” Perseus 785 ± 65 0.062 C 03 h 44 m 21 . 1 s − 43 o 32 0 00” Eridanus II 785 ± 65 M 03 h 59 m 48 . 3 s +67 o 08 0 19” UGCA86 2960 ± 232 0.918 C gi ▸ Nearby (<3 Mpc) 07 h 00 m 29 . 3 s − 04 o 12 0 30” HIZSS3A(B) 1675 ± 108 0.046 M ugi C g 09 h 16 m 02 . 2 s +52 o 50 0 24” UGC4879 1361 ± 25 0.215 C gi 09 h 34 m 53 . 4 s +17 o 03 0 05” LeoT 417 ± 19 0.037 C gi 09 h 48 m 56 . 1 s − 25 o 59 0 24” Antlia B 1294 ± 99 C g ▸ Isolated (>300 kpc from MW/M31) 09 h 59 m 26 . 5 s +30 o 44 0 47” LeoA 798 ± 44 0.055 C gi 10 h 00 m 00 . 1 s +05 o 19 0 56” SextansB 1426 ± 20 0.034 C gi 10 h 03 m 06 . 9 s − 26 o 09 0 35” NGC3109 DDO236 1300 ± 48 0.013 M ugi 10 h 04 m 04 . 1 s − 27 o 19 0 52” Antlia 1349 ± 62 0.011 M gi 10 h 11 m 00 . 8 s − 04 o 41 0 34” SextansA DDO75 1432 ± 53 0.046 M ugi ▸ Wide field imaging (u), g & i 10 h 21 m 45 . 1 s +18 o 05 0 17” LeoP 1620 ± 150 0.090 C gi 11 h 50 m 53 . 0 s +38 o 52 0 49” DDO99 2590 ± 167 0.053 C ig 12 h 12 m 09 . 1 s +36 o 10 0 09” NGC4163 2860 ± 39 0.050 C gi 12 h 18 m 46 . 0 s − 79 o 43 0 34” IC3104 2270 ± 188 0.065 M ugi 12 h 14 m 57 . 9 s +36 o 13 0 08” DDO113 2950 ± 82 0.049 C gi 12 h 27 m 40 . 9 s +43 o 29 0 44” DDO125 2580 ± 59 0.091 C gi ▸ CFHT MegaCam, Magellan Megacam 12 h 58 m 40 . 4 s +14 o 13 0 03” GR8 DDO155 2178 ± 120 0.066 M gi 13 h 30 m 44 . 4 s +54 o 54 0 36” UGC8508 2580 ± 36 0.227 C gi 13 h 54 m 33 . 5 s +04 o 14 0 35” and Magellan IMACS KKH86 2590 ± 190 0.053 M ugi 14 h 07 m 10 . 5 s +35 o 03 0 37” KKR3 2188 ± 121 0.047 C gi 14 h 15 m 56 . 5 s +23 o 03 0 19” UGC9128 2291 ± 42 0.038 C g 14 h 24 m 43 . 4 s +44 o 31 0 33” DDO190 2790 ± 93 0.100 C gi 16 h 13 m 48 . 0 s +54 o 22 0 16” KKR25 1905 ± 61 0.345 C gi 17 h 47 m 08 . 8 s − 64 o 38 0 30” IC4662 2440 ± 191 0.020 M gi 19 h 29 m 59 . 0 s − 17 o 40 0 51” SagDIG 1067 ± 88 0.019 C ugi 19 h 44 m 56 . 6 s − 14 o 47 0 21” NGC6822 DDO209 459 ± 17 0.018 C ugi 19 h 44 m 56 . 6 s − 14 o 47 0 21” Phoenix 415 ± 19 0.010 M ugi 20 h 46 m 51 . 8 s − 12 o 50 0 53” DDO210 Aquarius 1072 ± 39 0.026 M ugi C ugi 22 h 02 m 41 . 5 s − 51 o 17 0 47” IC5152 1950 ± 45 0.016 M ugi 22 h 32 m 41 . 2 s +31 o 12 0 58” 661 +152 AndXXVIII 0.051 C ugi � 61 22 h 40 m 43 . 9 s − 30 o 47 0 59” KK258 2230 ± 50 0.011 M gi 22 h 41 m 49 . 6 s − 64 o 25 0 10” Tucana 887 ± 49 0.024 M ugi 23 h 26 m 27 . 5 s − 32 o 23 0 20” UKS2323-326 UGCA438 2208 ± 92 0.021 M ugi 23 h 28 m 36 . 3 s +14 o 44 0 35” PegDIG DDO216 920 ± 30 0.061 C ugi 23 h 45 m 34 . 0 s +38 o 43 0 04” KKH98 2523 ± 105 0.053 C ugi

Why … DWARF GALAXIES ‣ Sensitive probes of galaxy formation and evolution Why … NEARBY ‣ Resolved stellar populations Why … ISOLATED ‣ Intrinsic properties of low mass galaxies Why … HOMOGENEOUS ‣ Need to minimize systematics

Local Group Subsample Alt. Names: WLM = DDO 221 UGC 4879 = VV 124 IC 1613 = DDO 8 distance to M31 DDO 210 = Aquarius NGC 6822 = DDO 209 Peg DIG =DDO 216 McConnachie 2012

Solo Dwarfs IC 1613 Leo T Sag DIG WLM Perseus Leo A 0.5°

Solo Dwarfs Full field of view IC 1613 Leo T Sag DIG WLM Perseus Leo A 0.5°

Analysis Techniques Resolved Stars Integrated Light Pros: Pros: Reveals faint and extended Describe the central ▸ ▸ stellar populations. regions well. Mass weighted rather than Colour profiles ▸ ▸ luminosity weighted. Can study the fainter old ▸ Combine both! RGB population. Kinematic tracers often RGB ▸ Cons: stars. Dominated by younger ▸ Cons: stellar populations. Incompleteness due to ▸ Heavily contaminated by ▸ Crowding in the central part foreground and Radial profiles are not in ▸ background sources. “conventional” units.

Resolved Stars in Nearby Dwarfs

Resolved Stars in Nearby Dwarfs

Extended Radial Profiles Surface Brightness Combine resolved stellar ▸ profiles with integrated light profiles in the i band . The g band is used in dwarfs ▸ with no visible integrated i band. Combine with parameter ▸ � . γ RGB Radius

Extended Radial Profiles Surface Brightness Similar “wings” observed by Bellazzini et al. 2018. Radius

Comparisons with Literature Values Comparisons to values compiled by McConnachie 2012

Preliminary! Trends/Future Work How does shape or size vary with distance? ▸ Indicative of tidal effects ▸ Trends with star formation histories? ▸ Reshaping due to internal processes ▸ Comparison to MW or M31 satellites, dwarfs ▸ in Fornax, M101 etc. External environmental effects ▸

Trends/Future Work Preliminary! Martin et al. 2018 Martin et al. 2018 find ultra faint MW satellites are increasingly flatter ▸ with decreasing luminosity. We find the brighter Solo dwarfs are more elliptical in general ▸

Exploring γ RGB � describes the fraction ▸ γ RGB of i band light resulting from the RGB stars. Dependent on spatially ▸ resolved star formation Larger fraction history, metallicity, age - from RGB stars metallicity relation, dust reddening… Redder

Summary Uniform and homogenous analysis of nearby isolated dwarf galaxies near the ▸ Local Group. Generate extended radial profiles to faint surface brightness limits. ▸ Study dwarfs collectively and individually. ▸ Clare Higgs higgs@uvic.ca @astrohigglet