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A proper motion study of the Lupus clouds using VO tools
(a collaboration with the SVO)
Francisco Jiménez Esteban (CAB & SVO)Belén López Martí (CAB) & Enrique Solano (CAB & SVO)
Gaia: II Reunión Científica de la REG, Santillana del Mar, September 2011
Gaia: II Reunión Científica de la REG, Santillana del Mar, Sept 2011 2
The Lupus clouds
One of the nearest low-mass star forming regions
d=140-220 pc
age<5 Myr
Star-count map by
Cambrésy et al. (1999)
Gaia: II Reunión Científica de la REG, Santillana del Mar, Sept 2011 3
The Lupus cloudsWithin or near the Gould Belt
xx
Gaia: II Reunión Científica de la REG, Santillana del Mar, Sept 2011 4
The Lupus cloudsThe stellar & substellar population: Most recent results
A large increase of the stellar and substellar population(but few spectra so far)
• Comerón (2008):
– Review of previous results.
– Lists 74 known members of Lup 1, 2, 3 & 4
• Merín et al. (2008):
– Spitzer c2d census of 159 PMS stars & candidates in Lup 1, 3 & 4
– Mostly objects with disks and/or envelopes
• Comerón et al. (2009):
– ~130 new cool, ~without envelope or disk, very low-mass members in Lup 1, 3 & 4.
Gaia: II Reunión Científica de la REG, Santillana del Mar, Sept 2011 5
Proper motions of Lupus members
• Sample: Compilation from Comerón (2008), Merín et al. (2008) & Comerón et al. (2009) 331 objects
• Method:– Multiple Cone Search using TOPCAT– Matching radius: 2– Astrometric catalogues: USNO-B1, SSS, PPMX and UCAC3– Purge resulting catalog using UCAC3 information:
• Errors != 0• Useful observations >3
Final sample: 178 objects
Goal: To check membership of proposed Lupus candidate members
Gaia: II Reunión Científica de la REG, Santillana del Mar, Sept 2011 6
Proper motions of Lupus members
Two kinematic groups!
Gaia: II Reunión Científica de la REG, Santillana del Mar, Sept 2011 7
Proper motions of Lupus membersLupus 1:The two groups have different
spatial distributions and proper motion directions.
Gaia: II Reunión Científica de la REG, Santillana del Mar, Sept 2011 8
Proper motions of Lupus membersLupus 3:The two groups have different
spatial distributions and proper motion directions.
Gaia: II Reunión Científica de la REG, Santillana del Mar, Sept 2011 9
Proper motions of Lupus membersLupus 4:The two groups have different
proper motion directions.
Gaia: II Reunión Científica de la REG, Santillana del Mar, Sept 2011 10
Proper motions of Lupus members
Group B is formed mostly by diskless stars, while Group A contains sources with and without disks.
Group B, as a whole, represent a later evolutionary stage than Group A.
Gaia: II Reunión Científica de la REG, Santillana del Mar, Sept 2011 11
Proper motions of Lupus members
The Group B sources tend to be brighter and redder than the Group A sources.
Their infrared colours are consistent with reddened background giants
(but also with reddened late K and early M-type stars).
Gaia: II Reunión Científica de la REG, Santillana del Mar, Sept 2011 12
Proper motions of Lupus membersComparison with Gould Belt populations
ROSAT Gould Belt stars (Wichmann et al. 1997) Upper Scorpius members (Bouy & Martín 2009)
Gaia: II Reunión Científica de la REG, Santillana del Mar, Sept 2011 13
Properties of Lupus kinematic membersGroup A sources with and without disks
Gaia: II Reunión Científica de la REG, Santillana del Mar, Sept 2011 14
Properties of Lupus kinematic membersEffective temperature
No trend (better precision required)
Gaia: II Reunión Científica de la REG, Santillana del Mar, Sept 2011 15
Properties of Lupus kinematic members
Physical parameters
No trend (better precision required)
Gaia: II Reunión Científica de la REG, Santillana del Mar, Sept 2011 16
Conclusions
• We have found two distinct kinematic groups in our compiled catalog of Lupus candidate members.
• The properties of the Group B sources (lower proper motions, location outside the cloud cores, virtual lack of sources with disks, optical and near-infrared colours) suggest that they are a background population or mixture of populations unrelated to the Lupus clouds.
• Group A sources have properties consistent with them being a genuine population of the Lupus clouds. Their proper motions are also consistent with those of other Gould Belt populations.
• We find no correlations between the proper motions and the properties of the Group A sources. More accurate measurements are required (Gaia).
Gaia: II Reunión Científica de la REG, Santillana del Mar, Sept 2011 17
More details in
López Martí et al., 2011, A&A, 529, A108
More details in
López Martí et al., 2011, A&A, 529, A108
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