Exploring GLIMPSE Bubble N107: Multiwavelength Observations and
  Simulations
  Context. Bubble N107 was discovered in the infrared emission of dust in the
Galactic Plane observed by the Spitzer Space Telescope (GLIMPSE survey: l ~
51.0 deg, b ~ 0.1 deg). The bubble represents an example of shell-like
structures found all over the Milky Way Galaxy.
  Aims. We aim to analyse the atomic and molecular components of N107, as well
as its radio continuum emission. With the help of numerical simulations, we aim
to estimate the bubble age and other parameters which cannot be derived
directly from observations.
  Methods. From the observations of the HI (I-GALFA) and 13CO (GRS) lines we
derive the bubble's kinematical distance and masses of the atomic and molecular
components. With the algorithm DENDROFIND, we decompose molecular material into
individual clumps. From the continuum observations at 1420 MHz (VGPS) and 327
MHz (WSRT), we derive the radio flux density and the spectral index. With the
numerical code ring, we simulate the evolution of stellar-blown bubbles similar
to N107.
  Results. The total HI mass associated with N107 is 5.4E3 Msun. The total mass
of the molecular component (a mixture of cold gasses of H2, CO, He and heavier
elements) is 1.3E5 Msun, from which 4.0E4 Msun is found along the bubble
border. We identified 49 molecular clumps distributed along the bubble border,
with the slope of the clump mass function of -1.1. The spectral index of -0.30
of a strong radio source located apparently within the bubble indicates
nonthermal emission, hence part of the flux likely originates in a supernova
remnant, not yet catalogued. The numerical simulations suggest N107 is likely
less than 2.25 Myr old. Since first supernovae explode only after 3 Myr or
later, no supernova remnant should be present within the bubble. It may be
explained if there is a supernova remnant in the direction towards the bubble,
however not associated with it.
