If the Spectrum of a Distant Galaxy Is Observed to Have

question 29

Multiple Choice

If the spectrum of a distant galaxy is observed to have a calcium K absorption line that occurs at a wavelength of 500.4 nm, what is this galaxy's distance if the rest wavelength of this absorption line is 393.4 nm? Assume the Hubble constant is 70 km/s/Mpc.

• A) 720 Mpc
• B) 950 Mpc
• C) 1,200 Mpc
• D) 2,600 Mpc
• E) 3,700 Mpc

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Definitions:

Residual Plot

A graphical representation used in statistics to visualize the difference between observed and predicted values from a regression analysis.

Trend Model

A statistical model that captures the underlying trend of a dataset by considering the long-term progression of data points.

Annual Time-Series

Data collected or recorded at regular intervals over a year, used in statistical analysis and forecasting.

Exponential Smoothing

A weighted moving average technique that applies decreasing weights to older data points, used for time-series data analysis.