Egorov O.V.1, Lozinskaya T.A.1, Moiseev A.V.2

1Sternberg Astronomical Institute, Moscow, Russia2Special Astrophysical Observatory of Russian Academy of

Science, Nizhnii Arkhyz, Karachai-Cherkessia, Russia

Nearby Dwarf Galaxies, 14-18 sep 2009

The dwarf irregular galaxy IC10 is a nearest sturburst galaxy

It have the highest number of WR stars per luminosity unit in the LG

The recent burst of star formation is localized mainly in its south-eastern part, where the densest cloud of HI, molecular CO cloud and complex of brightest emission nebulae locate. This region is brightest in Hα and [SII]λ6717 lines.

Marks on Marks on the the

imagesimages

Sources of Sources of gas gas

ionizationionization

• The observations were performed at the 6-m telescope (SAO RAS) with:1) SCORPIO focal reducer

operating in the scanning Fabry-Perot interferometer mode in Hα and [SII]λ6717 lines

2) MPFS field spectrograph

• All data reduction was provide in IDL.

We reanalyzed the 21-cm line data cube from VLA, kindly provided by Wilcots and Miller, to get more detailed local HI kinematics in the area of HL111 and HL106.

• Mosaic of CO clouds made using the data from Leroy et all (2006)

• All velocities are heliocentric

[SII]λ6717 pv-diagrams

The velocity of ionized gas in the starburst region is from V(hel) =-325 km/s to V(hel) =-350 km/s.

The mean value in Hα line is V(hel) = - 335 km/s. The expansion velocity of the bright HL111 and

HL106 shells is no more than 10-15 km/s. In some regions inside the HL111 shell we find profile

asymmetry in the red wing at the 2-6% of maximal intensity at the velocities from -250 km/s to -230 km/s

The weak details in the red wing of Hα line at 2-5% level in HL106 are in the range V(hel)=-280 km/s to V(hel)=-230 km/s.

The weak details in the red and blue wings are seen in the western part of the region between the HL106 and HL111 nebulae (their velocities above V(hel)= -260 km/s and V(hel)= -420 km/s)

Summary of the main results

There is the neutral shell directly outside the ionized nebula HL111. The mean velocity of this HI shell -333 -- -336 km/s. The expansion velocity of the neutral shell is about 10-15 km/s.

The similar neutral shell is distinguished around the nebula HL106; its expansion velocity is about 10-15 km/s.

There is the neutral shell directly outside the ionized nebula HL111. The mean velocity of this HI shell -333 -- -336 km/s. The expansion velocity of the neutral shell is about 10-15 km/s.

The similar neutral shell is distinguished around the nebula HL106; its expansion velocity is about 10-15 km/s.

In the region between HL106 and HL111 both smooth mean HI velocity changes from north-east towards south-west and the local perturbations of the neutral gas can be seen. The velocities of the “perturbed” neutral gas change in range from +30 km/s to -30 km/s relative to mean velocity.

Only in region where CO cloud locate the color excess reach a local maximum (E(B-V)=1.3)

Border of CO cloud concur with Hα shell.

We suppose that CO cloud locate in front of HL106 nebula and there is interaction between them

Probably the thin HL106 shell was formed as a result of photodissociation of the molecular gas on the border of CO cloud and ionization from the WR R10 and R2 and clusters 4-3 and 4-4

HL106Most probably M24 stars are located on the backside of densest HI cloud. We see a bright low-velocity details from coming side of blister-like shell and faint high velocity details from leaving side

We investigated the kinematics of the region of recent burst of star formation that contain a two brightest HII-region – HL111 and HL106. Based on results of this work we made assumptions about structure of this region

We found at first time a high-velocity details (about 100 km/s from the mean velocity) in cavern of HL111 and in HL106 nebula

We estimated a velocity of expansion of HL111 and HL106 (about 10-15 km/s).

We found neutral HI shells around HL111 and HL106 end estimate their expansion velocities (about 10-15 km/s).

The work is continuing and all results will be published soon

The work is supported by the Russian Foundation for Basic Research (project 07-02-00227) and is based on observation material obtained with the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences founded by the Ministry of Science of the Russian Federation (registration number 01-43).

Thanks for attention