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SUMMARY:Detection of density variations and off-track features in stellar 
 streams
DTSTART;VALUE=DATE-TIME:20230320T092000Z
DTEND;VALUE=DATE-TIME:20230320T093500Z
DTSTAMP;VALUE=DATE-TIME:20240704T115710Z
UID:indico-contribution-183@meetings.aip.de
DESCRIPTION:Speakers: Akshara Viswanathan (Kapteyn Astronomical Institute\
 , University of Groningen)\nLike any other galaxy in the universe\, eviden
 ce shows that the assembly of the Milky Way is irrefutably hierarchical. T
 he Galactic halo in particular has a nonlinear structure with a vast numbe
 r of cold stellar streams with complex morphologies that prove to be a pow
 erful test for the nature and distribution of dark matter in the halo.\n\n
 In this work\, we select halo main sequence stars using Gaia DR3 proper mo
 tion and photometry information\, the combination of which renders the red
 uced proper motion parameter. This parameter allows us to pick out high ta
 ngential velocity stars in halo orbits independent of the line-of-sight in
 formation. Our final catalogue consists of about 47 million halo main-sequ
 ence stars for which we can then determine precise photometric distances w
 ith typical uncertainties down to 7%. Our sample reaches out until ~20 kpc
  thereby probing much further out than would be possible using reliable Ga
 ia parallaxes.\n\nBinned velocity moments on the star map in the latitude\
 , longitude and pseudo-azimuth directions pop up several known tidal strea
 ms in the local halo - particularly retrograde structures\, due to the kin
 ematic selection. The use of main-sequence stars\, rather than brighter gi
 ants\, allows us to trace low surface brightness counterparts\, pushing th
 e substructure searches to Gaia’s magnitude limits.\n\nHere I will prese
 nt the substructures found and characterise them in more detail\, due to t
 he added information in derived distances and existing metallicities as we
 ll as the higher sensitivity in low surface brightness features. For these
  streams\, we resolve the gaps\, wiggles\, and density breaks reported in 
 the literature more clearly. The faint signs of disequilibrium in the form
  of kinks and density variations in these thin streams will paint a more d
 etailed picture of the existence and properties of the dark matter sub-hal
 oes that perturb them and in turn\, the mass distribution of our Galaxy.\n
 \nhttps://meetings.aip.de/event/20/contributions/183/
LOCATION:Haus H\, Telegrafenberg
URL:https://meetings.aip.de/event/20/contributions/183/
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