Please note, due to essential maintenance online transactions will not be possible between 02:30 and 04:00 BST, on Tuesday 17th September 2019 (22:30-00:00 EDT, 17 Sep, 2019). We apologise for any inconvenience.
To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
We report preliminary results from high-resolution UV spectroscopy of the super star cluster 1 in the nearby dwarf starburst galaxy NGC 1705, using HST-stis. These new observations can help us to quantify accurately the stellar content in this super cluster. Together with high quality spectra from SMC stars and the evolutionary synthesis code starburst99, we estimate an age for this cluster of 12±3 Myr, in agreement with previous studies. The measured dynamical mass and the theoretical L/M ratio suggest a normal IMF down to the hydrogen-burning limit.
Deep Chandra observations of NGC 3077, a starburst dwarf galaxy in the M81 triplet, resolve the X-ray emission from several supershells. The emission is brightest in the cavities defined by expanding shells detected previously in Hα emission. Thermal emission models fitted to the data imply temperatures ranging from 1.3 to 4.9 × 106 K. The total 0.3–6.0 keV X-ray luminosity is 2 − 5 × 1039ergs−1 (depending on the selected thermal plasma model). Most (85%) of the X-ray luminosity in NGC 3077 comes from the hot interstellar gas; the remainder comes from six X-ray point sources. The radial density profile of the hot gas is not as steep as that expected in a freely expanding wind (e.g., as seen in the neighboring starburst galaxy M 82) implying that the hot gas is still confined by the Hα shells.
Intergalactic metals are ubiquitous, but their sources remain unknown. A key constraint on these sources is the spatial distributions of metals. Yet, the clustering of metals is difficult to interpret along single lines-of-sight, because distance and velocity information are mixed in redshift space. To overcome this situation we are carrying out detailed comparisons between the line-of-sight and transverse distributions of metal line absorption systems observed in a large sample of QSO pairs and simulations including a wide range of IGM-enrichment scenarios. The degeneracy between distance and velocity is broken by the transverse information available in pairs of sightlines, and thus these comparisons are providing unique new constraints on when and where metals were ejected from galaxies.
Major mergers of gas-rich galaxies, each comparable in mass to the Milky Way, are rare at the present epoch. These events were readily identifed, however, two decades ago in far-infrared sky surveys (Soifer et al. 1986, 1987). Removal of the dust enshrouding these starbursts was almost immediately proposed as an evolutionary path to quasar formation (Sanders 1988). Recent measurements of the stellar velocity dispersion, rotation speed, and stellar surface brightness profile of these mergers suggest ULIRGs are indeed progenitors of field elliptical galaxies (Genzel et al. 2001; Tacconi et al. 2002).
We confirm the redshift of several z≃6 objects discovered by our imacs multislit emission-line survey. Their Lyα luminosities are lower than those of galaxies previously discovered using narrow-band imaging, as expected due to the excellent sky-supression inherent to this technique. Based on the line profiles of these objects, we argue that they are extremely young starbursts and find strong evidence for prominent galactic winds. This population of young galaxies is largely beyond the reach of current large surveys that use continuum selection.
Email your librarian or administrator to recommend adding this to your organisation's collection.