Related papers: A search for radioactive 26Al in the nova-like var…
We report on recent near-IR observations of V4332 Sgr - the nova-like variable that erupted in 1994. Its rapid, post-outburst evolution to a cool M type giant/supergiant, soon after its outburst, had showed that it was an unusual object…
L and M band observations of the nova-like variable V4332 Sgr are presented. Two significant results are obtained viz. the unusual detection of water ice at 3.05 microns and the fundamental band of 12CO at 4.67 microns in emission. The ice…
We present optical observations of the enigmatic nova-like variable V4332 Sgr. The importance of this object should not be understated since it is considered to be the possible prototype of a new class of eruptive variables. These objects…
Gamma-ray line emission from the radioactive decay of 26Al reflects nucleosynthesis in massive stars and supernovae. We use INTEGRAL 26Al measurements to characterize the distribution and characteristics of 26Al source regions throughout…
The Gamma Ray Imaging Spectrometer (GRIS) recently observed the gamma-ray emission from the Galactic center region. We have detected the 1809 keV Galactic 26Al emission at a significance level of 6.8-sigma but have found no evidence for…
V4332 Sgr is a red transient (red nova) whose eruption was observed in 1994. The remnant of the eruption shows a unique optical spectrum: strong emission lines of atoms and molecules superimposed on an M-type stellar spectrum. The…
A classical nova is an eruption on the surface of a white dwarf in an accreting binary system. The material ejected from the white dwarf surface generally forms an axisymmetric shell. The shaping mechanisms of nova shells are probes of the…
Al(26) radioactivity traces recent nucleosynthesis throughout the Galaxy, and is known to be produced in massive stars and novae. The map from its decay gamma-ray line suggests massive stars to dominate, but high-resolution line…
The isotopes $^{60}$Fe and $^{26}$Al originate from massive stars and their supernovae, reflecting ongoing nucleosynthesis in the Galaxy. We studied the gamma-ray emission from these isotopes at characteristic energies 1173, 1332, and 1809…
Gamma-rays from radioactive 26Al (half life ~7.2 10^5 yr) provide a 'snapshot' view of ongoing nucleosynthesis in the Galaxy. The Galaxy is relatively transparent to such gamma-rays, and emission has been found concentrated along the plane…
The origin of the long-lived radioactive 26Al, which has been observed in the Galactic interstellar medium from its 1.809 MeV decay gamma-ray line emission, has been a persistent problem for over twenty years. Wolf-Rayet (WR) winds were…
The Scorpius-Centaurus association is the most-nearby group of massive and young stars. As nuclear-fusion products are ejected by massive stars and supernovae into the surrounding interstellar medium, the search for characteristic…
The presence of radioactive $^{26}$Al at 1.8 MeV reflects ongoing nucleosynthesis in the Milky Way. Diffuse emission from its decay can be measured with gamma-ray telescopes in space. The intensity, line shape, and spatial distribution of…
With the SPI high-resolution spectrometer on INTEGRAL, new results have been obtained for long-lived radioactive 26Al and 60Fe in our Galaxy: 26Al sources apparently share the pattern of Galactic rotation in the inner Galaxy, and thus allow…
Measurement and astrophysical interpretation of characteristic gamma-ray lines from nucleosynthesis was one of the prominent science goals of the INTEGRAL mission and in particular its spectrometer SPI. Emission from 26Al and from 60Fe…
Since the Fermi discovery of $\gamma$-rays from novae, one of the biggest questions in the field has been how novae generate such high-energy emission. Shocks must be a fundamental ingredient. Six months of radio observations of the 2012…
Classical novae occur on the surface of an accreting white dwarf in a binary system. After ejection of a fraction of the envelope and when the expanding shell becomes optically thin to X-rays, a bright source of supersoft X-rays arises,…
Classical novae are important producers of radioactive nuclei, such as be7, n13, f18, na22 and al26. The disintegration of these nuclei produces positrons (except for be7) that through annihilation with electrons produce photons of energies…
Decades ago, $\gamma$-ray observatories identified diffuse Galactic emission at 1.809 MeV originating from $\beta^+$ decays of an isotope of aluminium, $^{26}$Al, that has a mean-life time of 1.04 Myr. Objects responsible for the production…
Recent observations of the diffuse Galactic gamma-ray glow at 1.809 MeV, attributed to the radioactive decay of 26Al, point towards a massive star origin of this radioactive isotope. Wolf Rayet stars and core-collapse supernovae appear to…