skip to main content

Search for: All records

Creators/Authors contains: "Adams, S."

Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher. Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?

Some links on this page may take you to non-federal websites. Their policies may differ from this site.

  1. Studies on graduate education have shown that underrepresented minorities finish PhDs in engineering at lesser rates and longer timeframes than their majority counterparts. While multiple interventions have been designed for students considering their decision to apply for graduate school or students completing their doctoral journey, few focus on the transition into those doctoral programs. To prepare minoritized doctoral students for this transition to the Ph. D., we developed and researched the Rising Doctoral Institute (RDI). The RDI is a four-day summer workshop for incoming doctoral students who identify as underrepresented in engineering and intend to begin graduate school in themore »Fall semester. This paper aims to discuss the process through which we developed the RDI and our initial research findings. We conclude with our plan to disseminate these workshops across multiple US institutions using a change-theory informed dissemination model.« less
  2. ABSTRACT SN 1954J in NGC 2403 and SN 1961V in NGC 1058 were two luminous transients whose definitive classification as either non-terminal eruptions or supernovae remains elusive. A critical question is whether a surviving star can be significantly obscured by dust formed from material ejected during the transient. We use three lines of argument to show that the candidate surviving stars are not significantly optically extinct (τ ≲ 1) by dust formed in the transients. First, we use SED fits to new HST optical and near-IR photometry. Secondly, neither source is becoming brighter as required by absorption from an expandingmore »shell of ejected material. Thirdly, the ejecta masses implied by the Hα luminosities are too low to produce significant dust absorption. The latter two arguments hold independent of the dust properties. The Hα fluxes should also be declining with time as t−3, and this seems not to be observed. As a result, it seems unlikely that recently formed dust can be responsible for the present faintness of the sources compared to their progenitors, although this can be verified with the James Webb Space Telescope. This leaves three possibilities: (1) the survivors were misidentified; (2) they are intrinsically less luminous; (3) SN 1954J and SN 1961V were true supernovae.« less
  3. ABSTRACT M31-LRN-2015 is a likely stellar merger discovered in the Andromeda Galaxy in 2015. We present new optical to mid-infrared photometry and optical spectroscopy for this event. Archival data show that the source started to brighten ∼2 yr before the nova event. During this precursor phase, the source brightened by ∼3 mag. The light curve at 6 and 1.5 months before the main outburst may show periodicity, with periods of 16 ± 0.3 and 28.1 ± 1.4 d, respectively. This complex emission may be explained by runaway mass-loss from the system after the binary undergoes Roche lobe overflow, leading the system to coalesce in tens of orbital periods.more »While the progenitor spectral energy distribution shows no evidence of pre-existing warm dust in the system, the remnant forms an optically thick dust shell at approximately four months after the outburst peak. The optical depth of the shell increases dramatically after 1.5 yr, suggesting the existence of shocks that enhance the dust formation process. We propose that the merger remnant is likely an inflated giant obscured by a cooling shell of gas with mass ∼0.2 M⊙ ejected at the onset of the common envelope phase.« less