PGC 57129 - Arp 188 - UGC10214 - VV29

Object: PGC 57129 the Tadpole galaxy in Draco, also known as Arp 188 which is classified as "Narrow filaments". The image field of view is 11.5'x10' with North down and East to the right.

Subimages L: 51 x 600 sec (8.5 hrs), rejected 20 other frames.
Subimages RGB: 18 x 600 sec + 9 x 1200sec binned 2x2 (6 hrs each)
Scope: C11XLT EFL=2945 mm (f/10.5 effective) with Pyxis 2" intrument rotator
Mount: Losmandy G11 with Gemini L4
Dome: Skyshed POD with zenith table
Camera: SBIG ST8XME+CFW10 (0.63"/pixel) set to -20C
Guiding: Self-guide, ExpTime = 2 sec, dithered
Acquisition and Processing: MaxIm DL/CCD v4.5 and v5
Imaged in May and June 2007 and 2008

Data for the 2 bright galaxies in the field from NED:
PGC 57129 14.4m, 3.6' x 0.8', type SB(s)c pec, distance 132 +/- 9 Mpc (~425 Mly), scale 36 Kpc/arcmin
CGCG 27-021 or MGC 09-26-54 15.5m, 0.5' x 0.4' type S0 or Elliptical, 4' SW from Arp 188

This distant galaxy has been the subject of a several investigations due to its dramatic tidal tail that extends over nearly 300 Kly (2.5' of sky). For comparison the Milky Way galaxy is only ~100 Kly in diameter, and one of the largest spirals, NGC 6632 is only 180 Kly in diameter. The spiral shape seems to have been stretched vertically like a spring from the interaction with the somewhat obscured interloper named VV29c. The collision, estimated to have occurred ~150 Myr ago, also set off considerable starburst activity in the tail and disk of the main galaxy VV29a. What has puzzled researchers is the lack of starburst activity in the nucleus of VV29a and has led them to dub Arp 188 an off-center ring-producing collision. Several very young and hot super star clusters populate the tail, two are massive and dense enough to rival a globular cluster or dwarf galaxies with over 105 solar masses, one is visible as the bluish-green dot half-way across the tidal tail, another fainter SSC is visible ~0.5' to the East. The "late type" S0 or elliptical galaxy CGCG 27-021 is associated with Arp 188 lying at the approximately same distance but seperated by at least 500 Kly.

The dynamics of the collision have been somewhat mapped out by radio telescope studies of neutral Hydrogen emission at the 21 cm line. The above diagram illustrates the flow of gas around the galaxy with positive velocities (with respect to the main recession velocity) being away from us, and negative velocities towards us. The East plume or tidal tail has a very low velocity delta (< 30 km/s) along it's length implying a stable filament unlike a regular spiral arm. A western plume, headed towards us, and a faint polar stream are visible in the highly linearly stretch version below. The nucleus of the intruder galaxy VV29c is visible as the bluish oval to the West of VV29a nucleus. VV29c is thought to lie ~300 Kly behind the disk of the main object and has approximately 1/7th the mass of VV29a.

The Astronomical Journal, Volume 131, Issue 1, pp. 261-281 (2006)
Remarkable Disk and Off-Nuclear Starburst Activity in the Tadpole Galaxy as revealed by the Spitzer Space Telescope
T. H. Jarrett, M. Polletta, I. P. Fournon, G. Stacey, K. Xu, B. Siana, D. Farrah, S. Berta, E. Hatziminaoglou, G. Rodighiero, J. Surace, D. Domingue, D. Shupe, F. Fang, C. Lonsdale, S. Oliver, M. Rowan-Robinson, G. Smith, T. Babbedge, E. Gonzalez-Solares, F. Masci, A. Franceschini, and D. Padgett

Astronomy and Astrophysics, v.380, p.418-424 (2001)
Did VV 29 collide with a dark Dark-Matter halo?
Briggs, F. H.; Möller, O.; Higdon, J. L.; Trentham, N.; Ramirez-Ruiz, E.