Massive Stars and their Siblings: the Extreme End of the Companion Mass Function

Project: Research project

Project Details


2) Objectives and Research Plan The involvements of various co-I that will supervise various aspect of their expertise is liste belowd under primary objectives. Three co-Is have more general leading roles. They are listed first. [De Mink, scientific PI, postdoctoral fellow, contributes at no cost to the project] De Mink will take care of the overall coordination of the project, the workflow of the project and facilitate communication between the various co-Is. Furthermore she will contribute to various aspects of the program. [Rajan, co-I, PhD student at ASU, 1 year of funding requested] Rajan gained expertise in high contrast imaging during his previous employment at STScI as a research and instrument analysis. He contributed to the design and testing and successful detection of planets using WFC3. This project will be a substantial part of his PhD thesis at Arizona State University. He will take the main lead in all steps listed below under primary objectives assisted and guided by the senior co-Is on this project. [Patience, co-I, staff at ASU, formal PhD supervisor of Rajan] Patience is an expert in stellar multiplicity and the detection of companions. She will directly supervise Rajan during various stages of the project. The primary objectives of this program are sixfold, given below in non-chronological order. A) Initial reduction and characterization of the bright stars (potential hosts) [Experts: Maiz-Appelaniz (at no cost), Lennon (at no cost), Sana (at no cost)] 1. Provide a drizzled, fully reduced high dynamic range mosaic of the center of the young nearby star cluster Trumpler 14 aligned with the archival data available of the region. 2. Provide a full photometric (and astrometric) catalogue of all bright sources containing the new photometry in the F139M and F127M bands 3. Reduce archival data of the same region to obtain accurate photometry in other bands. 4. Characterize the bright sources and assign a putative mass by comparison with the predictions of stellar evolutionary track. B) Detection of candidate companions [Experts: Soummer (at no cost), Pueyo (at no cost), Caballero-Nieves (at no cost)] 1. Create a library of top quality PSFs by creating post stamps and use the KLIP KarhunenLove Image Processing to create reference PSFs. We will investigate whether data from existing PSF libraries further enhances the quality. 2. This technique has been implemented in the ALICE pipeline specifically designed to reduce WFC3/IR and NICMOS data and has been successfully implemented to recover the HR8799 planets. However we need to optimize the pipeline for our non standard science goals. 3. Identify all companion candidates. Exclude spurious sources by checking their detection in the multiple exposures C) Characterization of the companion candidates [Experts: Sabbi (no costs), Robberto (no costs)] 1. Derive photometry (or upper limits) for all companion candidates. 2. Derive putative constraints on the mass of the companion candidates by comparison with stellar evolutionary tracks D) Proper motions (after 2nd epoch becomes available) [Experts: Bellini (at no cost), Sabbi (at no cost)] 1. Perform astrometric measurements to the accuracy needed for proper motion measurements 2. Derive the proper motion or upper limits 3. Derive the (probabilistic) implication for cluster membership and host-companion pairs versus chance alignment E) Deriving the statistical properties of the companions [Experts: Sana (at no cost), Maiz-Apellaniz (at no cost)] 1. Perform extensive artificial star tests to assess the sensitivity and completeness. 2. Perform Monte Carlo simulations adopting different underlying distribution functions for the companion-host properties and derive statistical constraints on the underlying distribution of various properties that characterize companion-host (distribution of separation, colors, average number of companions, host properties). 3. Evaluate the reliability and confidence intervals on the parameters that describe the underlying distribution functions F) Constraints& Interpretation [Experts: Tan (at no cost), Zinnecker (at no cost), Rahman (at no cost), Gies (at no cost)] 1. Interpret the results in the context of the predictions of models for massive stars formation. 2. Interpret the results in the context of models for feedback of massive stars on pre main sequence stars and their disk.
Effective start/end date4/1/143/31/17


  • National Aeronautics Space Administration (NASA): $50,546.00

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