Wine and Cheese Fall 2017 - Revision history

Kdkuntz: /* December 4th */

2017-11-28T01:20:10Z

December 4th

← Older revision		Revision as of 01:20, 28 November 2017
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	The HST CANDELS and CLASH programs have yielded observations of the most distant SNe Ia to date, 7 of which are at z > 1.5 and deemed suitable for cosmology. I will discuss how to obtain unbiased measurements of the expansion rate from raw SN Ia data and show that, when combined with a large compilation of lower-redshift SNe Ia, these high-z SNe usefully extend the Hubble diagram to allow a robust measurement of the expansion rate at z = 1.5. Current high-z SNe also help us distinguish "alternative" cosmological models from the standard Lambda-CDM model. Using simple model comparison statistics, I will quantify the extent to which some proposed alternative expansion histories (e.g., empty universe, power law expansion, timescape cosmology) are disfavored even with SN Ia data alone.		The HST CANDELS and CLASH programs have yielded observations of the most distant SNe Ia to date, 7 of which are at z > 1.5 and deemed suitable for cosmology. I will discuss how to obtain unbiased measurements of the expansion rate from raw SN Ia data and show that, when combined with a large compilation of lower-redshift SNe Ia, these high-z SNe usefully extend the Hubble diagram to allow a robust measurement of the expansion rate at z = 1.5. Current high-z SNe also help us distinguish "alternative" cosmological models from the standard Lambda-CDM model. Using simple model comparison statistics, I will quantify the extent to which some proposed alternative expansion histories (e.g., empty universe, power law expansion, timescape cosmology) are disfavored even with SN Ia data alone.

	=December ~~5th~~=		=December 4th=
	== Paul Butler (DTM) ==		== Paul Butler (DTM) ==
	'''Extrasolar Planets'''<br>		'''Extrasolar Planets'''<br>

Kdkuntz: /* December 5th */

2017-11-28T01:19:06Z

December 5th

@@ Line 138: / Line 138: @@
 =December 5th=
-== TBD (TBD) ==
+== Paul Butler (DTM) ==
-'''Title'''<br>
+'''Extrasolar Planets'''<br>
-Abstract
+Modern science began with Copernicus speculating that the Earth is a

Kdkuntz: /* November 27th */

2017-11-21T21:07:31Z

November 27th

← Older revision		Revision as of 21:07, 21 November 2017
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	=November 27th=		=November 27th=
	== ~~TBD~~ (~~TBD~~) ==		== Camilla Pacifici (GSFC) ==
	'''~~Title~~'''<br>		'''Synergy between galaxy models and observations to unveil the high-redshift Universe'''<br>
	~~Abstract~~		A synergy between galaxy models and data is indispensable to best exploit the capabilities of current and future telescopes. The interpretation of high-resolution data, both in terms of spatial and spectral resolution, will be challenging or even impossible without proper tools and comprehensive models. With the help of existing data, we need to develop and test new approaches that will allow us to deal with the amount of information we will receive in the future. I will present how we can generate a library of galaxy spectra where all components are computed in a consistent manner, using detailed star formation and chemical enrichment histories from cosmological simulations, state-of-the-art spectral models including nebular emission, and different treatments for dust attenuation. With such model spectra, we can simultaneously interpret spectral features and broadband photometry, from large scales to small regions inside a galaxy. I will show how this approach is being applied to current observations from CANDELS, SAMI, and the LEGA-C survey and how it will be used for future observations (for example JWST) to derive constraints on the dust and metal content of high-redshift galaxies.
			== Dan Shafer (JHU) ==
			'''Confronting alternative cosmological models with the highest-redshift Type Ia supernovae'''<br>
			The HST CANDELS and CLASH programs have yielded observations of the most distant SNe Ia to date, 7 of which are at z > 1.5 and deemed suitable for cosmology. I will discuss how to obtain unbiased measurements of the expansion rate from raw SN Ia data and show that, when combined with a large compilation of lower-redshift SNe Ia, these high-z SNe usefully extend the Hubble diagram to allow a robust measurement of the expansion rate at z = 1.5. Current high-z SNe also help us distinguish "alternative" cosmological models from the standard Lambda-CDM model. Using simple model comparison statistics, I will quantify the extent to which some proposed alternative expansion histories (e.g., empty universe, power law expansion, timescape cosmology) are disfavored even with SN Ia data alone.

	=December 5th=		=December 5th=

Kdkuntz: /* Caroline Huang (JHU) */

2017-11-13T02:09:45Z

Caroline Huang (JHU)

← Older revision		Revision as of 02:09, 13 November 2017
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	== Caroline Huang (JHU) ==		== Caroline Huang (JHU) ==
	''''''<br>		'''A Near-Infrared Period-Luminosity Relation in NGC 4258'''<br>
	~~Abstract~~		The improving precision of H0 measurements has opened up a possible conflict between two methods of inferring it. Local measurements of H0 show a 3.4-sigma discrepancy with the value derived from observing the cosmic microwave background and assuming a Lambda-CDM cosmology. The most precise local measurements of H0 currently rely on Cepheid variables to calibrate nearby supernovae. However Cepheids will likely be difficult to find in the future with JWST. Mira variables can serve as an alternative distance indicator, allowing a check of Cepheid distances while increasing the calibrating SN Ia sample. I will present the results of a year-long observation of Miras in the water megamaser host galaxy NGC 4258 and discuss the process of discovering and characterizing Mira variables for use as distance indicators.

	== Yajing Huang (JHU) ==		== Yajing Huang (JHU) ==
	'''Studying Cosmology Through the Cosmic Microwave Background'''<br>		'''Studying Cosmology Through the Cosmic Microwave Background'''<br>

Kdkuntz: /* November 13th */

2017-11-08T15:33:04Z

November 13th

← Older revision		Revision as of 15:33, 8 November 2017
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	=November 13th=		=November 13th=
	== Jonathan Aguilar (JHU) ==		== Jonathan Aguilar (JHU) ==
	''''''<br>		'''Discovery of a red substellar companion to an A star'''<br>
	~~Abstract~~		We present near-infrared spectrophotometry and L-band photometry of a newly discovered early L/late M companion to an A-type star. The companion orbits at a separation of 19 AU and is ~10^-4 times fainter than its host. We place our companion in context with the known population of isolated brown dwarfs and brown dwarf-/planetary-mass companions, and attempt to explain its strangely red color.

	== Kirsten Hall (JHU) ==		== Kirsten Hall (JHU) ==
	'''Infrared Galaxies Clustered Around Quasars Across Cosmic Time'''<br>		'''Infrared Galaxies Clustered Around Quasars Across Cosmic Time'''<br>

Kdkuntz: /* Brooks Kinch (JHU) */

2017-11-07T20:14:47Z

Brooks Kinch (JHU)

← Older revision		Revision as of 20:14, 7 November 2017
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	== Brooks Kinch (JHU) ==		== Brooks Kinch (JHU) ==
	''''''<br>		'''Fe K-alpha Line Profiles from Black Hole Simulations'''<br>
	~~Abstract~~		Both stellar-mass black holes and AGN are commonly observed with prominent and asymmetrically broad Fe K-alpha emission lines in the X-ray band. These line photons originate deep within the gravitational well of the black hole and are gravitationally redshifted as they make their way out---the resulting line profile contains information about the spacetime geometry surrounding the black hole and, therefore, otherwise elusive black hole properties such as spin. We have developed a novel approach to generating template Fe K-alpha line profiles starting with 3D GRMHD simulations and applying as much relevant physics as possible; I will describe the process, show some results, and draw comparisons to observations and to existing techniques.

	=November 27th=		=November 27th=

Kdkuntz: /* Yajing Huang (JHU) */

2017-11-07T17:13:51Z

Yajing Huang (JHU)

← Older revision		Revision as of 17:13, 7 November 2017
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	Abstract		Abstract
	== Yajing Huang (JHU) ==		== Yajing Huang (JHU) ==
	''''''<br>		'''Studying Cosmology Through the Cosmic Microwave Background'''<br>
	~~Abstract~~		Given the importance of Cosmic Microwave Background (CMB) constraints for current and future cosmology, it is crucial that results from CMB measurements are carefully examined. I test the internal consistency of Planck temperature power spectrum by splitting the data into high and low multipole ranges and find tension between their inferred parameters. I also compare the results from Planck to those from external CMB or non-CMB datasets and find that a discrepancy at the level of 2-3 \sigma exists between parameters inferred from high multipoles data of Planck and other measurements. I also describe an ongoing effort to calculate the correlation between Planck and WMAP temperature results so as to quantify their consistency.

	== Brooks Kinch (JHU) ==		== Brooks Kinch (JHU) ==
	''''''<br>		''''''<br>

Kdkuntz: /* Kirsten Hall (JHU) */

2017-11-07T17:07:33Z

Kirsten Hall (JHU)

← Older revision		Revision as of 17:07, 7 November 2017
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	Abstract		Abstract
	== Kirsten Hall (JHU) ==		== Kirsten Hall (JHU) ==
	''''''<br>		'''Infrared Galaxies Clustered Around Quasars Across Cosmic Time'''<br>
	~~Abstract~~		Powerful quasars can be seen out to large distances. As they reside in massive dark matter halos, they provide a useful tracer of large scale structure. We stack Herschel-SPIRE images at 250, 350, and 500 microns at the locations of 13,000 quasars in redshift bins spanning 0.5 < z < 3.5. While the detected signal is dominated on instrumental beam scales by the unresolved dust emission of the quasar and its host galaxy, at z~2 the extended emission is clearly spatially resolved on Mpc scales. This emission is due to star-forming galaxies clustered around the dark matter halos hosting quasars. We measure radial surface brightness profiles of the stacked images to compute the angular correlation function of dusty star-forming galaxies correlated with quasars. We generate a halo occupation distribution model in order to determine the masses of the dark matter halos in which dusty star forming galaxies reside. We are probing potential changes in the halo mass most efficient at hosting star forming galaxies. We find evidence that this halo mass evolves with redshift in a manner consistent with "cosmic downsizing".

	== Caroline Huang (JHU) ==		== Caroline Huang (JHU) ==
	''''''<br>		''''''<br>

Kdkuntz: /* Ira Thorpe (GSFC) */

2017-10-30T15:14:02Z

Ira Thorpe (GSFC)

← Older revision		Revision as of 15:14, 30 October 2017
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	=November 6th=		=November 6th=
	== Ira Thorpe (GSFC) ==		== Ira Thorpe (GSFC) ==
	'''~~Title~~'''<br>		'''LISA - Taking the Gravitational Wave Revolution to Space'''<br>
	~~Abstract~~		With detections of multiple black hole systems and now a neutron star merger, the long-promised era of gravitational-wave and multi-messenger astronomy is finally upon us. As exciting as LIGO and VIRGO's accomplishments are, they represent just the first few glimpses through this new window. Among the most promising avenues for future discoveries is a space-based gravitational wave observatory such as the Laser Interferometer Space Antenna (LISA). Consisting of three spacecraft in a triangular constellation millions of kilometers on a side, LISA will be sensitive to gravitational waves in the milliHertz band. The population of astrophysical sources expected in this frequency band is rich, including millions of compact binaries in our own galaxy, the capture of stellar remnant objects in nearby galactic nuclei, and the merger of massive black holes in the distant universe. In this seminar, I will give an overview of the LISA science case, the mission concept, the required technologies, and the current status of the mission.

	=November 13th=		=November 13th=

Kdkuntz: /* November 13th */

2017-10-23T17:30:12Z

November 13th

← Older revision		Revision as of 17:30, 23 October 2017
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	=November 13th=		=November 13th=
	== ~~TBD~~ (~~TBD~~) ==		== Jonathan Aguilar (JHU) ==
	'''~~Planning Solar System Observations with JWST~~'''<br>		''''''<br>
			Abstract
			== Kirsten Hall (JHU) ==
			''''''<br>
			Abstract
			== Caroline Huang (JHU) ==
			''''''<br>
			Abstract
			== Yajing Huang (JHU) ==
			''''''<br>
			Abstract
			== Brooks Kinch (JHU) ==
			''''''<br>
	Abstract		Abstract