Stripped gas as fuel for newly formed HII regions in the encounter
  between VCC1249 and M49: a unified picture from NGVS and GUViCS
  Context: We study the peculiar interacting galaxy system of VCC1249/M49
located in the core of the Virgo B subcluster. Owing to a recent interaction
between the dwarf galaxy VCC1249 and the halo gas of the gE M49, neutral
hydrogen has been displaced from the interstellar medium of this dwarf into the
Virgo ICM. Observations also reveal multiple compact star-forming regions that
are embedded in this HI cloud, with a projected separation up to 13 kpc from
VCC1249 in the northwest direction.
  Aims: Motivated by recent NUV imaging from GUViCS of the VCC1249/M49 system
that shows significant ongoing/recent star formation in the compact regions, we
aim to constrain the origin of these outlying HII regions with a
multi-wavelength approach.
  Methods: Using deep optical (u, g, i, z) imaging from NGVS and new Halpha
imaging obtained at the San Pedro Martir observatory together with Keck
long-slit spectroscopy, we characterize the SFR, ages, and metallicity of
VCC1249 and its outlying compact regions. Moreover, we analyze the color and
luminosity profile of the galaxy to investigate its recent interaction with
M49.
  Results: Our new observations indicate that VCC1249 underwent a recent
interaction with M49 in which both ram-pressure stripping and tidal interaction
occured. The joint action of the two mechanisms led to the removal of the HI
gas from the ISM of VCC1249, while the gravitational tides triggered the
stellar tail and counter-tail of VCC1249. Our SED analysis reveals that the
star formation in this galaxy was truncated around 200 Myr ago and that the
outlying HII regions were born in situ about 10 Myr ago out of pre-enriched gas
removed from the dwarf galaxy. These observations also reveal that interactions
between central and satellite galaxies similar to the one between VCC1249/M49
may be an effective way of dispersing metals into the halos of massive
galaxies.
