New ultracool subdwarfs identified in large-scale surveys using Virtual Observatory tools: II. SDSS DR7 vs UKIDSS LAS DR6, SDSS DR7 vs UKIDSS LAS DR8, SDSS DR9 vs UKIDSS LAS DR10, and SDSS DR7 vs 2MASS

N. Lodieu, M. Espinoza Contreras, M. R. Zapatero Osorio +4

We aim at developing an efficient method to search for late-type subdwarfs (metal-depleted dwarfs with spectral types >M5) to improve the current statistics. Our objectives are: im…